How To Make A DIY PWM Tester
Sometimes you come across to repair power supplies, monitor, TV or some other devices containing SMPS. Many power supplies have a PWM IC. Most of them are UC384X. Testing of an IC with multimeter is a difficult process or inaccurate. There is an easy way to test a suspected PWM IC. In this article you will able to make PWM Tester by using and old CRT monitor board.
1. Arrange an old CRT monitor from Junk. Keep in mind that the power section has a DIP 8 PWM IC and is ok.
2. Remove PWM IC from board.
3. Take a DIP 8 IC socket and fit in place of PWM IC which you removed.
4. Now your cheapest PWM IC tester is ready
5. Insert a suspected PWM IC into socket and switch on power and observe weather power LED light up or not. A good IC will give response in form of power LED light up.
This article was contributed by Daud Asi from Pakistan.
simeon
May 18, 2012 at 10:52 am
Thank you for the isightful trick . I could not have got it from anyone else.
Alex Lee
August 30, 2012 at 2:26 am
Currently toubleshooting a Razer Mako speaker. The speaker works for a few seconds, then goes into ticking mode (no more sound except ticking from speakers). When the ticking stops about a few minutes later, the speaker goes back to normal (and continues to function as it should). I've tried many things but no go. I shorted the optocoupler pins at the SMPS primary side and the ticking starts again until I remove the wire. Noticed that it uses 3845 PWM I.C. Could that I.C be at fault? Thanking in advance.
Jestine Yong
August 30, 2012 at 9:48 pm
Hi Alex,
First you need to disable that supply to the speaker section and if there is no more ticking then something could have been shorted downstream. If the output voltages fluctuates then check the power supply especially the e-caps.
Jestine
Tommy Turza
June 1, 2013 at 5:44 am
Hello,
sorry for crashing in on this, but I have found this thread while looking for a solution for the Mako "ticking sound of death" problem.
My unit is at a very qualified microelectric engineer's workshop right now and we're trying to isolate the cause - any help or information that you might have uncovered can be pretty useful! Do you have any ideas how to repair that?
Thanks!
Tommy
Jestine Yong
June 1, 2013 at 10:17 am
HI Tommy,
What type of equipment was that?
Jestine
Tommy Turza
June 3, 2013 at 9:35 pm
Hello Jestine,
a Razer Mako 2.1 THX high-end speaker system, having been discontinued by Razer years ago and not supported any more. The system has a very distinct way of breaking down, it's a worldwide phenomenon, and nobody published anything on the net about how it could be mended. With part of the community we're working on a solution in the following forum:
http://forums.whirlpool.net.au/archive/1739055
but nothing came up yet. We'd be grateful for any professional input on this, the speakers are exceptionally rare now and very unique, finding a way to repair them would be more than welcome.
Thanks!
Tommy
Jestine Yong
June 4, 2013 at 7:45 pm
HI Tommy,
Hope there will be someone that is able to answer the question.
Jestine