Thursday, July 30, 2009

Preher TV Online Store

We just launched our online store, please visit today by clicking here, or by clicking on the photo below. We will be adding more fun stuff soon and also would love suggestions, please email me at john@preher-tech.com with your ideas. Thanks and have a great day.


Tuesday, July 28, 2009

Testing MOSFET(Metal Oxide Semiconductor Field Effect Transistor)

Here is some good info on testing MOSFET transistors, one link uses a DMM and the other link is from my friend Jestine Yong, he shows you how to test a MOSFET using an analogue meter and I must say I really prefer Jestines testing methods. Click here for link 1 and Click here for link 2, also click on the photo below for another great link on testing MOSFETs.

How to test BJT(Bi-polar Junction Transistors)

Recently one of my news letter subscribers wrote me looking for some information on testing BJTs, so I thought this would be a good topic for the Blog. Here are 2 links to some good information on testing a BJT , click here for link 1 and click here for link 2 you can also click on the photo below.

August News Letter

Don't forget to sign up for our FREE monthly electronics news letter, if you have not already signed up do it now by clicking here. Every month Preher TV will send out a news letter packed with electronics information and August's news letter will also be the release of my new book on electronics repair including LCD TV repair. Don't miss out, again if you are not a subscriber start today by clicking here or by clicking the photo below.

Saturday, July 25, 2009

Making Electrical Measurements Part 3:

The third part on making electrical measurements. Click here to read part 3. These three articles just touch the surface, to learn much more about making measurements and testing electronic components you must read a good book on the subject, like "Testing Electronic Components" or "Electronic And Electrical Servicing", these are great books and by reading them not only will you have gained great amounts of knowledge but you will also have completed the first 2 necessary steps towards getting a CETG apprentice certification.




Making Electrical Measurements Part 2: Loading

Second part of Making electrical measurements.Click here to read more.

Making Electrical Measurements Part 1

Here is part one of a good article for taking electrical measurements, this is something you should feel very comfortable doing if you want to be an electronics repair technician, if you want to feel comfortable it is essential you know what you are doing..Click here to read more.

Wednesday, July 22, 2009

Lot's of work!!!


Sorry I have taken so long to update the blog lately, but I have been very busy the last week. LCD TV repairs are increasing constantly and the demand for qualified technicians to do warranty TV repairs is greatly increasing. This is great news for me as I can make some good money. Also I have been working hard on my book so that coupled with the extra work lately has made it hard for me to get online and blog. I now think I am organized enough that I can start updating regularly. Today I will catch the blog up by posting multiple times today, Have a great day.

Beware B.I.C. (blue star international components)

Beware of blue star international components, I have used them in the past with no problems, but I usually don't because they are over priced. This time I made an order because my normal distributor did not have the part I needed in stock and I needed it fast. Well guess what? These guys sent me a used refurbished convergence IC, it looked like it was pulled from a junk pile!!! it had rust on the back even!!! And guess what, it didn't work, I had to order another one from some where else to fix this customers set, and refund the customer the express shipping on that used part.I have emailed blue star international components asking them how they will resolve this and why they would send me this horrible used part when I was purchasing a new one, they have failed to respond and chose to ignore me. Oh well my business will never use this horrible company again, and I urge any of you that use this company to be aware they are using bad and illegal business practices. Be careful of anywhere you buy parts and stick with your trusted distributors.

Don't use these guys they do bad business, BEWARE!!!!
http://www.bluestar-online.com/


(Edit 7/30/09)
Well I have to say that although I have never received a response from Bluestar , I did notice today that they refunded me the money for the IC, when checking my bank account. I'm glad they refunded my money but it really does not excuse selling that "rebuilt" STK393-110.

Wednesday, July 15, 2009

Tools And Test Equipment

Pro'sKit is a company I like to by some of my tools from. They are very nice for the price. Pro'sKit also offers a variety of test equipment.Check them out today by clicking here or by clicking the photo below.

Monday, July 13, 2009

Schematic And Parts List(astable DJ)

Here is the Schematic and the parts list for the "Astable DJ" circuit featured on our project page recently.Visit the project page by clicking the photo below.


Parts List:

R1,R2 = 330 Ohm resistor
VR1,VR2 = 22k Ohm variable resistor
D1 = red 3mm LED
D2 = green 3mm LED
D3 = P6KE24A
C1,C2 = 10uF @ 16 volts capacitor
Q1 = D600K NPN
Q2 = C3228 NPN
SW1 = any SPST switch


Please note, these are just parts I pulled off an old board to put this circuit together.The components I used are definitely not the only or best choices, please play around with the parts you have laying around and see what works best.

Friday, July 10, 2009

Mitsubishi - Blinking Green Light

Here is some info on a very common repair for mitsubishi projection TVs.I myself have done a few of these DM module repairs.Hope this might help some of you that have seen this problem and not found a solution.Click here and also click on both photos below to get alot of info on this common repair.
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Simple DC to DC converter

Here is a simple circuit for converting a DC voltage to another DC voltage, I thought this was a pretty cool little circuit that might be useful in a project sometime.Click here or click on the photo below to read more about this circuit and some of it's possible applications.

Electronics Website

Electro-Tech-Online is a cool forum I have been going to lately.I enjoy reading the threads and posts.There are many knowledgeable people on this site and it is also nice to help out when you can.Check out the website by clicking here or by clicking the photo below.



Wednesday, July 8, 2009

New Project,LED Flasher

Here is our latest recycling project, using broken electronic devices from around the shop.This is a simple astable mutivibrator using variable resistors for an adjustable time constant.The parts list and schematic will be available soon on our project page, click here to visit the project page.Enjoy the video clip.


Sunday, July 5, 2009

Nuts And Volts Magazine

I think everyone involved in electronics should get a subscription to a good electronics magazine.It's good for refreshing the mind and keeping up with new advancements as well.I personally subscribe to Nuts And Volts, This months issue included "build the transistor clock" which was a really great article and looks like a fun project.The article also included some info on Flip flops, Decoders and Counters. Nuts And Volts also includes many cool advertisements for the electronics enthusiast along with all the great articles to read.To Check out Nuts And Volts magazine today click here or click on the photo below.

Friday, July 3, 2009

Email Support For CETG

Our certification program CETG(Consumer Electronics Technicians Group) is now offering email support to help with the course part of the certification program.We will help you with any questions or concerns you have while reading the study material and getting ready for the test.We will be available for you as an instructor 24 hours a day to help with your course, and we will assist you all the way to certification.The email support program is a great deal at only $40.00 USD.And remember CETG certification is available to anyone in the world who speaks and reads english, you will be able to test at a local testing center, by phone or online your choice.Click here to find out more about the email support program or click here to get more information on the CETG.Or you can click on one of the photos below.










Thursday, July 2, 2009

Schematic Diagrams

eserviceinfo.com is a good website to get service manuals and schematic diagrams.Having the right information like service material or schematics for the electronics device you are working on can seriously reduce the time you spend trouble shooting.Click here or click on the photo below to visit this great website.