Monday, January 25, 2010

Samsung HPT4254 (HPT4254X/XAA) BN44-00161A Power Supply Repaired.

HPT4254X/XAA, BN44-00161A Professional Repair:
If you are interested in having a BN44-00161A, BN44-00162A or any other power supply repaired professionally then you may be interested in our mail in repair services. We can do the repair on BN44-00161A and BN44-00162A power supplies for $50 plus the cost of return shipping and handling. Click here to see our mail in repair service page.


HPT4254X/XAA, BN44-00161A Repair Kits:
Repair kits for the BN44-00161A and BN44-00162A power supply available from Preher-Tech.
Click here to visit our parts kits sales page.


Had a service call today for a Samsung HPT4254 (HPT4254X/XAA) Plasma TV. Customer said he went to bed with the TV on and when he woke up the TV was ticking, tick, tick, tick etc... no response when the power button was pushed and he had to unplug it to turn it off. When I arrived I plugged the TV in and it still had the symptom. After opening the TV , I removed the PSU(Power Supply Unit) and discharged the large filter capacitors in the primary side of the PSU and then checked the board for bad/cold solder connections, and checked the ESR of all the electrolytic capacitors on the board, and checked the fuses. All capacitors tested good, found very bad ring cracks on MOSFETs QX801 and QX802 and re-soldered these connections. I found that fuse F803 was open, so I checked the corresponding circuit including MOSFETS QS801 and QS802, both MOSFETs were shorted, one between gate and drain and one between gate and both drain and source. After replacing Both shorted MOSFETs and F803 the TV turned on and functioned normally. Hope this helps some of you that have the same failure with this model TV. MOSFETs QS801 and QS802 were both FQA13N50CF.

Note: See all updates below.



Update: 04/16/2011:

We have seen many more of this model TV with the same failure symptom as described above but with a different cause of failure and this cause of the failure seems to be most common so we are posting it now as we realize a lot of people are looking to fix this TV.

The components we are commonly finding have failed are,

F803 is open.

QX801 and QX802 are shorted or have totally blown.

RX802, RX803, RX832 and RX833 are open or have a seriously increased resistance.

RX804 and RX805 are open or have a seriously increased resistance.

DX803 and DX804 are open or completely blown.


Component values:

F803= 8A 250V Time Delay/Slow Blow 5mm X 20mm

QX801 and QX802= FQPF9N50C

RX802, RX803, RX832 and RX833= 20 ohm

RX804 and RX805= 10k ohm

DX803 and DX804= 1SS184T5LFT(this is the part we use for replacement)



Picture showing replaced SMD components on the bottom of the PSU.


HPT4254X/XAA, BN44-00161A Professional Repair:
If you are interested in having a BN44-00161A, BN44-00162A or any other power supply repaired professionally then you may be interested in our mail in repair services. We can do the repair on BN44-00161A and BN44-00162A power supplies for $50 plus the cost of return shipping and handling. Click here to see our mail in repair service page.


HPT4254X/XAA, BN44-00161A Repair Kits:
Repair kits for the BN44-00161A and BN44-00162A power supply available from Preher-Tech.
Click here to visit our parts kits sales page.



Update #2 05/09/11:

We have done many more repairs on BN44-00161A and BN44-00162A power supplies since the last update and have found another failure that happens on a small percentage of them.

Components that may have failed,

QS803, QS804, QS805 and QS806 one or more shorted(check for open junctions as well)

DS823 shorted(may be open as well) check between pin 1 and 3

RS859 may be open or have a seriously increased resistance

U804, if many of the components listed above are bad then you should also replace the Resonant Mode Controller IC



Component values:
QS803 and QS804= NPN 20V 2A SMD BJT(marking ZG)

QS805 and QS806= PNP 20V 2A SMD BJT(marking ZH)

D823= 18V 0.35W SMD zener diode(marking 8Y)

RS859= 4.7 ohm SMD resistor

U804= MC33067P power controller IC




Locations for both of the controller/sub PCBs




Location of power IC



Location of QS803, QS804, QS805, QS806, DS823 and RS859


HPT4254X/XAA, BN44-00161A Professional Repair:
If you are interested in having a BN44-00161A, BN44-00162A or any other power supply repaired professionally then you may be interested in our mail in repair services. We can do the repair on BN44-00161A and BN44-00162A power supplies for $50 plus the cost of return shipping and handling. Click here to see our mail in repair service page.


HPT4254X/XAA, BN44-00161A Repair Kits:
Repair kits for the BN44-00161A and BN44-00162A power supply available from Preher-Tech.
Click here to visit our parts kits sales page.



Don't forget to visit http://www.preher-tech.com and remember if you ever have any electronics related
questions you can always email contactus@preher-tech.com for support.


117 comments:

  1. MOSFETs QX801 & QX802
    What are the part numbers?
    I have same problem but QX801 & QX802 are both
    fried and need replacing.

    ReplyDelete
  2. Sorry I did not record the part numbers for those two transistors. I will see if I can find a service manual for that model and grab the part numbers for you.

    ReplyDelete
  3. How can i tell if those parts are fried or not by looking at them?

    ReplyDelete
  4. By testing them with my digital and or analogue multi-meter.

    ReplyDelete
  5. I can buy that for $20 from a lowes or homedepot. I've never used it before though... should the tv be on or does it detect without power running thru the board? Thanks for responding so quick!

    ReplyDelete
  6. When checking resistance as you will be doing on the fuse and across the junctions of the transistors you want the power off and the TV unplugged. Only voltage, current and waveform checks are done with power on and in that case you need to be using an isolation transformer.

    ReplyDelete
  7. Can i measure resistance without removing the transistors or fuses from the board? Im getting readings on the power supply board on random pieces that i tested. The fuses are giving me 0.01 on 200 Ohm and 1. on all the higher settings. Is there a way to easily identify if its the power supply board or the main board? thanks alot!

    ReplyDelete
  8. What is your TVs symptoms? You can test them in circuit, if they test bad, pull them and test again to make sure. Look for low resistance between gate/drain and drain/source. For more info on testing MOSFETs and different testing techniques look here, http://preher-tech.com/tools_and_tips.aspx

    ReplyDelete
  9. QX801 & QX802 = FQPF9N50C is the P/N

    ReplyDelete
  10. Anyone have the part #s for Q5801 & Q5802? I have the same problem with my set.

    ReplyDelete
  11. Hi, I have same problem with my samsung 42 inch plasma tv. I found out that QX801 and QX802 in PSU are fried. Tried to replaced it. But when i turned ON the TV, I heard clicking sound continuesly. SO I unplugged the tv and check the resistance of fuses and mosfet. Found out that F801 & F803 are busted. QX802 pins are shorted. Can you tell what is the possible cause of this problem. I would really appreciate if you can give me some advise to find the problem and what is the possible solution to fix the problem. many thanks

    ReplyDelete
  12. Could be that the primary coil of the transformer, that the MOSFETs are switching has shorted windings, or possibly the secondary side diodes in that circuit are shorted.

    ReplyDelete
  13. I was wondering where can this mosfet 13N50CF be purchased? Radioshack? i need it and dont have a clue thanks

    ReplyDelete
  14. You won't find one at radio shack, use this from suburba electronics....

    http://www.suburban-electronics.com/display/FQPF13N50C/FQPF13N50C

    copy link and paste it in your browser....

    ReplyDelete
  15. Thank you so much I really appreciate it

    ReplyDelete
  16. where can i buy the fuse at? whats the part # for it?

    ReplyDelete
  17. The value of the fuse is written on it's end caps, you can buy the fuse at suburban electronics or at MCM to name a couple.

    ReplyDelete
  18. Can you test those mosfets while they are on the board or do you have to remove them first? Also how do i know which one is the base collector and emitor? I am kind of uneducated about electronics and trying to fix the tv by myself.

    ReplyDelete
  19. No remove the MOSFETs from the board to test, also MOSFETs have a gate, source and drain they are not like a BJT. Here is a link to the datasheet so you can find the pin configuration, http://datasheetz.com/FAIRCHILD/FQPF13N50CF/FQPF13N50CF.html , look for shorts between gate to source and gate to drain. If you need more assistance email me john@preher-tech.com

    ReplyDelete
  20. I think I have a similar problem. My tv will not turn on, it just clicks and clicks. If you push the power button, the blue light will turn on for a few seconds and turn off, the tv will just keep clicking away.

    I tested the mosfets in circuit and all 4 are not testing good. I want to pull the mosfets out for further testing, but it seems as though they are mated really well to the heat sink. How do I get those off the heat sink without damaging them?

    ReplyDelete
    Replies
    1. Use a small pair of pliers and grasp on each side of the body of the mosfet, hold tightly and pull it away from the heatsink.

      Delete
  21. This post has been the most helpful resource for helping me diagnosing the problem with my set. The MOSEFETs I have been having problems with are ICX805 and QX806. QP802 and QP803 could also be bad but I need to pull all of these from the board and retest. Do you know what the part numbers are for these MOSFETs? I am have problems figuring out what MOSFETs are needed. I saw the link for the other ones on Suburban.

    ReplyDelete
  22. hello john you have some great tutorial, i've got a bush lcd tv model number idlcd37tv07hd. it's a strange fault but i'll try and explain the first time i looked at this tv the customer said you could watch it but if you unplug it from the wall it wouldn't work then some times it would work so i replaced the capacitor in the secondary side and when you plugged it back in it sprang back to life but now the tv is back with the same fault there is 322 volts at the primary filter capacitor scratching my head at the minute mate any info would be great mate thanks for your time regards shaun

    ReplyDelete
  23. This posting is a GREAT information. My HPT4253 has the exact same symptom. I devided to check the QX801 and QX802 MOSFETs. I took the screw off of 801 and I notice that the MOSFET was loose. If it was attached to the circuit board, it should not be loose. It was broken solder. Factory defect. After I solder the QX801 and back on to the board and I check the others. Other solders looked OK. I put the board back in and presto!!! TV is working now. It was a bad solder from factory... Thanks for the info.

    ReplyDelete
  24. Hey glad to hear about your success. I have also received numerous emails from people who have also repaired their TVs using the info from this post and I am happy to know I have helped so many people. Take care.

    ReplyDelete
  25. John I have been watching your post and my tv seems to be having the same problems - can you suggest one place to buy both 13N50CF and fqpf9n50c I can't seem to find one place for both. Thank you for any help.

    ReplyDelete
  26. Mouser has both in stock....

    http://www.mouser.com/ProductDetail/Fairchild-Semiconductor/FQPF9N50CF/?qs=sGAEpiMZZMvECErq9cesgF7YqTCjEhPAyE74ad%252bdTrI%3d

    http://www.mouser.com/ProductDetail/Fairchild-Semiconductor/FQPF13N50CF/?qs=sGAEpiMZZMvECErq9cesgMR5%2fzdudHhwPB1ernQ%252bDsY%3d

    ReplyDelete
  27. thank you John I have ordered both they should arrive in 3 days and I will be back in touch - you are the best!

    ReplyDelete
  28. helpful info for sure; I have replaced the 2 220uf 450v and the 1 680uf 250v Capxon caps which were bulging. Tv worked for a few hours and now back to the clicking and power cycling. I've read of a possible relay that might be bad - any validity to this? how about the fuses #803 etc... would it even attempt to power up if any of these were blown? would they be visibly blown like a similar glass fuse? Anyhing else that I might test? I would appreciate any further info. thanks,
    iamdmc.

    ReplyDelete
  29. John I received the MOSFETs today from Mouser and replaced them plugged the tv in and still just clicking - any other suggestions?

    ReplyDelete
  30. Did you also replace F803? Was it open? Also you may want to check the electrolytic capacitors in the PSU as they have also been known to fail and cause the same symptoms in this model.

    ReplyDelete
  31. Does anyone know the part values for these locations?


    * DX804
    * RX803
    * RX832
    * DX803
    * RX802
    * RX833

    AS I see these have failed and a couple burned up. :(

    ReplyDelete
  32. Hi John,

    I see you added a link to the transistors needed for this fix on Mouser, can you also post a link to the fuse you mentioned and any capacitors that could possibly be needed to be replaced. I have a HP-T4254 with the same problem and I'm planning on ordering the parts needed to repair it and I would like to order all the part that might be bad all at once.

    Thank you,

    Jerry

    ReplyDelete
  33. With days of research on internet for clicking problem in my Samsung HPT-4254X/XAA, found this post to be the best explained one. Appreciate all the information. I removed the PSU and noticed that the two transistors QX801 and QX802 are completely fried and one of the solder in QX801 was also broken. I ordered two FQP9N50C from eBay. I removed the screw from the QX801 but unable to remove the MOSFET from the heatsink. It seems glued to it. Can you please advise how to remove the MOSFET from heatsink without damaging the board or the heatsink.

    Thanks for all the information.

    ReplyDelete
  34. Pry the part with a flathead screw driver. Your glue thermal compound and will be needed to install the new part.

    ReplyDelete
  35. Hello Vijay,

    The MOSFET is stuck because of the dried up heat sink compound between it and the heat sink. Use a slotted screw driver or some type of flat metal tool to pry it off of the heat sink and make sure to clean off the old heat sink compound and apply more to the new MOSFET when replacing it.

    ReplyDelete
  36. Hi, I've the same problem. Found the mosfets were shorted when they were in the circuit. replaced them. no change. discovered the original mosfets were fine once taken out. so the short was elsewhere.

    Then i got the service manual. Here is an interesting page about troubleshooting the power supply.
    http://img249.imageshack.us/img249/8779/screenshot20110127at184.png
    The voltages it refers to are on the 20 pin output to the main board. the std_5v at the top is pin 3 on this board i think. testing pins 3 and 4 gives 5v for me. but trying to test the 12v or 5.3v output shows nothing. So maybe ICX808 etc need testing. Whats the best way to test these?

    ReplyDelete
  37. Where can I buy the fuses for this? Any help with be appreciated!

    I replaced the capacitors but no change. Now I'm going to change out the MOSFET's and Fuses and see what happens.

    ReplyDelete
  38. Hi I have the same issue and called samsung and of course they offered no assistance, but to take it in for repairs. qx802 was opened and when my husband looked at the back of power supply there was a burn mark. I could not tell if the one fuse is opened though. does the entire power supply need to be replaced?

    ReplyDelete
  39. Just got my Power Supply Board fixed through Preher-Tech! Best decision that I have made. The service was great and they were very quick in both in getting the PSU back and responding to questions. This is by far the best way to fix your PSU!

    ReplyDelete
  40. Can you test/fix the ymain? Put a new power supply board in and still didnt have a picture and after a few moments one of the chips on the ymain sparked. Can I send it to you?

    ReplyDelete
  41. Yes we can fix the Y main, but you will also want to replace the Y buffers along with the repaired Y main as there is most likely a bad buffer board as well and that is what caused the Y main to go. The IGBJTs on the Y main are most likely shorted. The repair will run about $45 plus return shipping.

    ReplyDelete
  42. Had mine repaired my John and could not be happier with the repair process.

    ReplyDelete
  43. Just wanted to say thanks for your repair service! I got the power supply board for my HPT4254 back over the weekend, and it brought the set back to life! It's been running great since, works like new. Your email support was top-notch too - fast, friendly, and helpful. Much appreciated!

    ReplyDelete
  44. Checked my PSU out all components and solder joints are good had no blown fuse either. I see in a previous post talk of the Y main. What is this? How can I determine if it is bad or what else beside the PSU can cause the good audio but no picture problem.

    ReplyDelete
  45. Hello; I am working on repairing one of these SamSung power supplys. The two power FETS QX801 + QX802 have sides blown off. There was a "fire" under the PCB in this area when the 4 20 ohm resistors burned up along with diodes DX803 and DX804. I believe this "fire" ruined the 2 10K resistors RX804 and RX805. One measured 17k and other 20k. I also noticed what probably is causing the failure of these boards. #1 is the heat sink compound has dried out for QX801 + QX802 causing over heating. #2 all 6 pins of QX801 + QX802 have cracked solder at the PCB. I would recommend that if you have one of the sets that you remove QX801 + QX802 and clean and reapply heat sink compound and properly solder QX801 + QX802 to the PCB. John / J. D. Electronics. Poland Spring, Maine

    ReplyDelete
  46. What I have is a HP T5054 Samsung.
    What happens , plug in clicks a few times , comes on picture & sound
    (sometimes for few minutes), shuts off clicks , sometimes recycles.
    Have just time to measure voltages they appear fine untill shut down.
    Tried cold spray does not seem heat related , does not seem mechanical
    niether.
    Resoldered Mosfets & other area no differance.
    Caps all look fine & seems to measure fine with ESR.
    PSU still clicks with Y & Z dissconnected.

    I can not seem to locate problem.
    I hope you have some ideas , The TV is not worth so much anymore so can not
    spend too much time on.

    ReplyDelete
    Replies
    1. I have same poblem did you get a fix

      Delete
  47. This is a great thread! Thanks to all.
    Found a TV on the street. Had the same problem. Blue light, clicking relay.
    I went through all the comments and checked all the mosfets and their circuits and everything was fine.
    Unplugged all the plugs going to the power board one at a time. The clicking stopped only when I unplugged the cable to the main board with all the in/out ports on it.
    Was stumped for a while but finally found a solder bridge on ICX803.
    FIXED!

    ReplyDelete
  48. I have another Samsung HP T4264 , which is from same family of PSUs as the HP T5054.
    Same type of clicking as the 50 inch version.
    Except stays on longer several minutes before recycles.
    This must be common fault ?
    Any ideas ?
    Mosfets break under load or what ?
    B&G

    ReplyDelete
  49. Could I just replace the entire power supply board?

    ReplyDelete
  50. Yes replacing the power supply is definitely an option, although it is a more expensive option and the new power supply will very likely eventually have the same failure as the original. Take care.

    ReplyDelete
  51. Thank you very much for all the useful info here John! Fixed mine by replacing a few of the parts, though most seemed to be ok. I only had a relatively cheap DMM to test with, but the fuse was good and the MOSFETs turned on. The cap tester can't go up to 2200uF, so not sure if those were the issue, but I replaced the four MOSFETs and two caps and it's working great now.

    ReplyDelete
  52. Hi everyone. Thanks John for so many helpful tips here. My HPT4234X screen energizes when i turn it on and the power light blinks five times and the relays cycle every 20 seconds. The screen is not bright and I have no access to controls or menu. Anyone have any thoughts? Plus does anyone know where I can get a glimpse of a trouble shooting tree fot this? I already did the above tests and found no bad mosfets, caps, or fuses. Any help would be very appreciated. I'm trying to get this back to life for a friend for Christmas. Thanks in advance.
    Chris

    ReplyDelete
  53. Had same clicking issue with my HPT4254 so sent it to John Preher after reading this blog. Received it back a few weeks later, put it back in the TV and voila, it worked! Has been good for a week now. Price was best I could find, $50 to fix and $15 added for return shipping. Cost me a total of $77. Highly recommend John's services.

    - Pete

    ReplyDelete
  54. I bought my Samsung HP-T4234 used this summer in Florida and then took it back home to Canada. After a month or so it started shutting off and clicking. I found Preher Tech and this blog on line when I researched the problem. I e-mailed John who was very quick to answer my questions and confirm that I had the all too common power supply (PSU) failure. The local Samsung recommended repair shop estimated $125 to $250 to repair my TV. That was too rich for me so I mailed the PSU board to Preher-Tech in mid-December. It was quickly repaired for the great price of $50 and mailed back to me. My TV now works perfectly. I'm 100% satisfied with Preher Tech and I commend John for taking the time to publish so much helpful information on the internet.
    Peter

    ReplyDelete
  55. I used this excellent blog and the detailed information it contains to source replacement components and to instruct a local electronics whiz what to remove and resolder on the PSU. His work was done for the bargain price of two bottles of fine Australian wine. The TV now works like a charm and I feel very clever. John I would have sent it to you to fix but Brisbane, Australia to Edmonds, Washington USA is a long long way !!

    ReplyDelete
  56. John is really a great guy. It is nearly impossible to find someone that will repair at the component level and it is even more shocking that he is willing to share his valuable information for the rest of us. I found one other comment online that mentioned the bad mosfets but that was it. This is the only place I could find any information about the bad components on the board.

    I am extra lucky to have such a great company local in Washington!! I will be using Preher Tech exclusively from now on!! Thank you John!!

    ReplyDelete
  57. Okay there aren't many things I won't try and repair myself inspite of being a girl. The problem is I have no idea what MOSFETs, PSU's, wingdings, or buffer boards are. I do however know Samsung offered me a bunch of BS which didn't help at all so I need mine fixed please John. Just tell me what to unscrew how to package and where to send this POS so I can have my TV back please.

    Can you tell I'm frustrated?

    ReplyDelete
  58. Hello Yvette,

    I just sent you an email.

    ReplyDelete
  59. I have a HP-T4234 that is making the clicking sounds and turning off and on and working intermittently. I have read a dozen websites about faulty Samsung TV's over the past few hours and they all say that the fix is to simply replace a couple of capacitors. Then I came across your article and you say the culprits are a fuse and some MOSFETs. I'm confused!

    ReplyDelete
  60. I just repaired same problem. Replaced QX801 AND QX802...AND back to working great! AL

    ReplyDelete
  61. HP-T4264 would not power on. Fuses not blown yet. Found broken solder joints on two of the mosfets. Resoldered them, and so far so good for the first 5 mins!

    ReplyDelete
  62. I now have a working tv thanks to Preher-Tech!!! I cannot thank ya'll enough!!and if anyone has doubts about sending something to them for repairs,then that is a big mistake cause they are awesome!! I am one happy girl =)

    ReplyDelete
  63. Hello John, I need your email address. I think it might be simpler to sent you the board....I'm struggling just trying to remove the back panel :/

    ReplyDelete
  64. jmj41066

    You can email me at john@preher-tech.com

    ReplyDelete
  65. I have samsung HPT4254x/xaa and is making clicking sound (wont turn on) which kit do you recommend I purchase? Took back off of tv and everything looks ok

    ReplyDelete
  66. I read all of these problems people had with power supply replaced board know when tv is pluged in it only makes a clicking noise i unplug each board sepratly and when unpluging the mother board it stops anyone have this problem i looked and dont see no physical damage

    ReplyDelete
    Replies
    1. Look very close at the solder connections of G S and D for both QX801 and QX802 they may need re-soldered.

      Delete
  67. This is great forum/thread. I've been working on my Samsung HPT4254X/XAA (Purchased fall, 2008) for over two weeks now trying to resolve what I believe is a power supply issue. I've been using Youtube and threads like this to self diagnose but I'm starting to feel overwhelmed due to my lack of intimate knowledge of electronics. I’ve already invested $50 into saving this tv in an effort to avoid spending well over $1000+ for a new one (I would go smart TV).

    Per what I’ve read and watched I've replaced all the fuses (5 x 20mm 8Amp & 6.3Amp 250 Volt ceramic), checked the capacitors (no swelling or blown) and I still haven't been able to resolve the issue. I've checked for “cracking” and "rings" on QX801 and QX802 as well. I’m using a crappy RADIO SHACK 15 RANGE POCKET DIGITAL MULTIMETER which I’m almost certain I’m not using correctly.

    - Tried to check fuses for continuous flow but all it does (under OHM) is range up and then return to zero. Should they have continuous flow when tested? Let’s take a step back, please confirm I should have it set to OHM?

    Thinking of replacing entire power supply board, is $150 market for this? I only see on listed on Ebay being shipped from Miami.

    Does anyone have any pics, visuals are helpful for the MOFFIT testing/replacing/installing?

    Thanks,

    JWG

    ReplyDelete
  68. I'm with JWG. YouTube would be a godsend.

    ReplyDelete
  69. Any chance the amazing John with Preher-Tech would do a YouTube video for us?

    ReplyDelete
  70. I finally replaced the entire power supply board via a purchase off E-bay and the TV is working again. Glad I went through the steps to identify all possible issues before purchasing the most expensive replacement option. This is a great website full of great information and dialogue.

    ReplyDelete
  71. I have the same problem with the clicking, I plugged it in today and it turned on for a couple of minutes, any suggestions

    thnx

    John

    ReplyDelete
  72. Are you still offering the repair service? Mine just died with the same symptoms. Thx.

    ReplyDelete
  73. I haven't have time to say thank you, i had this problem with my TV, but i found this great blog that help me to fix it. Now i have 6 months since i repaired my TV and it still working pretty good.
    Thanks John from Mexico border with Laredo Texas.

    ReplyDelete
  74. I have replaced blown up qx801 and qx802 all the 20 ohm res and the smd and 10ks. I have a schematic. Set will not power up and no clicking. Troubleshot the ckt. Found that i have no ps-ok It is 3.3v. I ground the psok pin and relays click on and va ps is up. Vs ps is still off but troubleshooting tells me that is becausse vson signal is 0v. What generates the psok and vson signals?

    ReplyDelete
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    phone solution please visit following site.

    Gsm Repairing Solution
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    ReplyDelete
  76. I've been reading this blog in an attempt to diagnose the problem with my Samsung HPT4264. It makes an intermittent clicking noise when I plug it in. I understand this is likely from the power relay on the power supply board. I tried replacing a few caps and MOSFETs but still had the problem. I ended up ordering a used power supply board on ebay that was supposedly in working condition. After installing the replacement board the clicking continued. I disconnected one connector at a time and found that the clicking stops when I disconnect CN801 on the power board from CN101 on the main board. I assumed a bad main board and ordered another used main board from ebay. Replaced the main board tonight and the clicking remains. Now I'm confused as to whether the problem is with the power board or the main board. I have looked over the boards and cannot see any obvious problems.

    I would appreciate any thoughts or ideas. I'm already $175 into this "repair" and I'm hoping for some return on my investment.

    ReplyDelete
  77. Same issue.... was doing the "clicking" ....
    replaced the 4 Mosfets and now it turns on.... but not all the way.
    the LED flashes 4 times and then the LED turns off.
    If you press buttons on the remote, it flashes like it's responding.
    It's driving me nuts....
    Any ideas?
    Call/text me at 702-771-8310
    I'd HIGHLY appreciate it.
    By the way .... besides the HPT-4254 having the "clicking" issue... I also have a 50" Samsung HPT-5064/5054 with picture quality issues....

    Someone help me!!
    ;)

    ReplyDelete
  78. Just received my board back from Preher-Tech and my 42" Samsung is running perfectly. Was going to try and do the repairs myself but by the time I purchased all I needed to do the work, it was easier to send it out. Turn around time was very fast and at a very reasonable price. Do not have a local shop take $200 from you. Send it to Preher-Tech. Thanks again for your service!

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  79. Replaced power supply and still clicks the clicking stops when I unplug the main board with the inputs and also when I unplug the Y board or the logic board I believe it is called the clicking stops as well and it makes a power on sound. Any ideas if all 3 of these boards are bad?

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  80. I replaced a few caps that looked a little swollen but tested fine I was checking the fuse and noticed that when input just a little pressure on the fuse side jumper jp135 is connected to the tv stops clicking and powers on as soon as i let off the tv powers off relay starts clicking again re solder the connection for the fuse holder and checked other solder joints all apear to be fine but still will only power on when putting pressure on the fuse....any suggestions?

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  81. Looked over all of the solder joints again and touched up a few that looked bad and now it is working which is good because I tested just about all of the components on the board and none of them were bad all were working properly...from what I have seen posted I think samsung needs to quality check the process the manufacture of their power supply is using to produce these boards.

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  82. Seems like on all the Mosfets outer two legs I get continuity, but on ICX805 I do not. Should I see continuity on that one also?

    Rich

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  83. I have a HP-T4254. Would not turn on so I replaced the two 25v 1000uf and two 35v 470uf at the bottom of the PSU (below two tranformers). This was based on other site that recommended these. Two of the capacitors were bulging and two were not. After this the set would turn on, but after about 5-10 minutes would go off and click until unpluged. After reading Austin Moore's comments, I went back and checked solder joints, primarily the Mosfets. I resoldered the QS801, QS802, QX801, and QX802 since the joints looked deteriorated and these are the components most mentioned in prior messages. The TV seems good now. It ran for over 5 hours without failing. I think there could be failures in the solder joints due to the excessive heat and age. These components are running between 120 and 140 degrees. The TV was made in 2007.
    Therefore, it would seem possible that replacing bad capacitors and resoldering the main mosfets could be worth a try before replacing components. It should be noted that I had found that having a fan blow on the back with the cover off, prevented failure also, so temperature was shown to be an issue. Failed solder joints can work when cold and fail at higher temperatures.
    Hope this helps.

    Richard

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  84. PeanutBoy you are definitely correct in thinking the faulty solder joints are due to excessive heat at the location of the MOSFETs and also due to the solder used which cannot withstand the the major changes in temperature that occur on those lands. I would recommend you replace those MOSFETs even though your TV is functioning normally now as their integrity has likely been diminished during the fault and you will only get about a month or two of normal operation before you hear a load bang when the MOSFETs blow taking DX803 and DX804 along with them and most likely a couple of the 20 ohm resistors as well. If you replace QX801 and Q802 now you can avoid that. Thanks for commenting and have a great day.

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  85. Anyone found anywere in the uk for parts qx801? Can find them anywere here

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  86. Kit available from ohmsupplies for UK customers,
    http://www.ohmsupplies.co.uk/epages/62027733.sf/en_GB/?ObjectPath=/Shops/62027733/Products/KIT67

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    Replies
    1. Thankyou thats a big help

      Delete
  87. Ok.replaced the two lower mosfets.still clicking .the clicking stops when i remove the cable for the board with the inputs and audio sockets on.my soldering leaves a lot to be desired tho, i cant seem to get the solder to go into the hole to get a good connection,it just kinda sits on top in a blob .any tips ?

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  88. Helping a friend who's 51 inch Samsung Plasma TV (model PN51E450A1FXZA) won't display anymore. The TV powers on, there is a red box/image that flashes on the upper left and then the screen is black. The TV is powering, the Samsung light on the bottom middle of the TV frame is lit but that is it.

    I've read it could be as easy as the TV being on the wrong "Source" but I don't believe that is the issue. I pulled the back off and there is no sign of capacitor issues.

    Anyone have any experience with this?

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  89. Nice post! Glad that you like their service. I believe that treating the customer so politely makes them so comfortable with your services. Anyway, thanks for sharing. Keep posting.

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  90. Hello.. I guess my original comment didn't post for some reason.. I have had a t4264 for over a year or two that would not turn on after suffering from clicking/cycling. I came across this site a couple times in the past, finally opened up the tv, found 2 bulging capictors with yellow coming out. CX819 and CX816. I replaced them with 1000uf 35v and put it back together. YAY! She turned on and ran for about 5 hours straight. Note: I installed this tv in a corner near an AC and with a vornado fan aimed at the rear to help keep her cool. 69 degrees approx. in that location. After 5 hours. click click turned off.. She turned back on in the morning for 3 minutes then off.. I cant see any physical damage to any parts.. Is there any guide anywhere on which of the most common failing parts are and how to test them and their values? Also, the tv sat for a year but I did attempt to discharge using a 10k capacitor and a decharging tool I made with a long pvc pipe, wire, clips and resitors.. But can someone give me advice on the proper procedure(actually where to grab and how to remove the board, and exactly how someone would discharge this step by step?) This is my first project like this, and Im learning as I go! Chad bigpips@gmail.com

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  91. I had the same fault, tv clicking and not turning on. Checked all fuses ok. Then on closer inspection found 3 dry joints on QX801, the same as this video link http://www.youtube.com/watch?v=za3EixgxBkk
    After re soldering, tv power up fine.

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  92. Only re-soldering MOSFETs QX801 and QX802 is a temporary fix and they will typically blow 2-3 months later at most. They should definitely be replaced.

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  93. Great feed! I have a Samsung 42" Plasma TV (HPT4254X) and was experiencing the clicking on/off issue and then heard a pop. I opened up the TV and noticed a burn mark on the back of the PSU. I replaced the PSU. TV came on for 30 minutes before it turned off and the clicking resumed. Could the brand new PSU be bad or is there another potential issue?

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  94. The new power supply likely failed. It must have been used or it was refurbished and the repair was not done properly. There is also a small chance you now have a Y-sus and or Y-buffer failure, but it is much more likely your new power supply failed. This is quite common unfortunately. Many people are selling used ones that have not even been refurbished as new and unused.

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  95. Hi, I have exactly same problem with my tv. I'm trying to remove the back panel to see if it has same defects, but the back panel doesn't come off. I unscrewed all and tried to lift it off, but it seems like it is stuck on mid bottom part where all the jacks go. anyone has any idea what should i do to remove the panel?

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    Replies
    1. Don't forget to remove the little flat head screws where the blue PC jack enters the unit, as well as the nut at the base of the coax jack.

      Delete
  96. I just recently started having this issue as well. Usually what I get is the TV will pop and turn off then turn back on and keep working. A few times though it has turned off and just continues to click resulting in me pulling the power and plugging it back in then it fires back up till the next time it happens. I pulled the back off yesterday and noticed the 2200 and 1000 microfarad caps were bulging and one looks like it had a little leak as well. I am wondering though if I should just go ahead and spring for the whole refurb kit they sell and just replace all the possible bad components while I am in there. I would say my soldering skills are above average and have repaired a few TV's as well by replacing caps. TV has been great since we bought it and still has a good picture IMO, so 75 bux to hopefully fis it all up is pretty cheap.

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  97. Hello Mark,

    The complete repair kit is a great choice and contains the components necessary to repair the current fault and to prevent future failures as well. If you have any trouble with the kit installation, after purchasing a repair kit from Preher-Tech you can send in the board at anytime and we will complete the repair at no charge granted there is no other repairs that need to be performed and that the board has not been damaged by the customers attempted repair.

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    Replies
    1. Well I just ordered the full monty kit. Good thing to as the TV has started doing more frequently. Question thouhgh, does the kit come with any diagram(s) as to where the replacement components go? Most are pretty obvious but just wondering.

      -Mark

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  98. Hello Mark,

    Thank you for your business. We do not supply a diagram with the kit but we do give email support through contactus@preher-tech.com and we are happy to guide you through the repair as needed, so don;t hesitate to email as much as necessary for support. Have a great day.

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  99. Good Blog. Same clicking issue with my Samsung HP-T4254.
    First replaced the four capacitors as other site suggested but the clicking issue continue.
    Later find this blog and replace all the four mosfets and the TV now work properly.
    Haven't check the old mosfets died, loose or not, simply replace them as suggested.
    Hope the TV will work for a few more years.

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  100. hi i have this same problem i took out my psu and it is burned a little bit by the dx803 and 804 along with the rx832 i dont know weather i should try replacing them myself or if thats even possible.. i can send a picture if needed. my main question is do u think u can fix it and if not do you have a extra psu for the t4252 thanks!!

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    Replies
    1. Yes this board is definitely repairable. Please email us at contactus@preher-tech.com for more information. Have a great day.

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  101. If you haven't got any idea about electronics DO NOT try to repair the power source as you can kill yourself. I had few mosfets dead on my power source and the chips from the controller. I have change them but the QS 803 to QS806 are dead so I'm waiting them and done. I hope. :)

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  102. this tutorial helpful for me,
    now i can repair my hpt4254,
    thanks a lot

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  103. I emailed you twice via your form so I can send you the board 7/27 and 7/29/14, so far no answer.. please advise

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  104. looking for this,
    and will try to repair
    thank so much

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  105. Hello
    I need some help regarding my 5V st by voltage. I only have 3,2V on st by and I have changed the ICB802 (Viper22A); ICQ805 (KA7815E); QQ802;QQ803, capacitors and diods as well but still 3,2V. I have replaced the TB801 still the same problem. What can I do?

    Thanks

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  106. I recently mailed the power board from my Samsung 42 inch TV to you and had a rapid turn around time. Thanks. It was "clicking" as all of those other were doing. Problem is...when I installed the circuit board, the clicking stopped but I did not get any video at all, whereas before I sent the board, I was getting temporary video then blank screen. It comes on great now but even hooked up to Direct TV and trying all of MY known tactics to get the monitor screen to light up, I have not been successful. Any advice?

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  107. I replaced CX816 and CX819 which were two 1000uF 25V CapXcon capacitors bulging and leaking at the top vent. I put in Nichicon VZ series of the same values. Also notice the TV would only stay on when I applied pressure to the main heatsync the FET's are screwed into. As soon as I let go of the heat sync, the TV would turn off and cycle on/off. I resoldered all the FET's along this heat sync and now its been two days of straight operation with no issues. Hopefully the TV lasts for a few more years to come. Yeah only 720p, but the color accuracy is phenomenal for this generation of TV.

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  108. Thank for all those posts...that make my Samsung HP-T4364 plasma tv works again!
    Mine have the same clicking problem. First I inspect the capacitors on power supply board and just one seems damaged, but I changed all 10 capacitors....with big expectations. But same clicking came again. Then I discover this post and decide to change the 4 mosfet QX 801 and 802 and QS801 and 802....and magic happen...my TV works again! Spend just $40 to fix that! Thank you guys!

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