Comments on: Problems In Isolator IC https://jestineyong.com/problems-in-isolator-ic/ Semiconductors, Test Equipments, Circuit Board Troubleshooting, Electronic Repair Courses and Many More! Sun, 07 Mar 2010 20:14:33 +0000 hourly 1 https://wordpress.org/?v=5.4.19 By: admin https://jestineyong.com/problems-in-isolator-ic/comment-page-1/#comment-4859 Sun, 07 Mar 2010 20:14:33 +0000 https://www.jestineyong.com/?p=2657#comment-4859 HI Noel,

Thanks for sharing!

Jestine

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]]> By: Noel https://jestineyong.com/problems-in-isolator-ic/comment-page-1/#comment-4845 Sat, 06 Mar 2010 02:05:24 +0000 https://www.jestineyong.com/?p=2657#comment-4845 Hi Jestine,

I have experience in repairing SMPS with output of +12V,-12V and +5V keep blowing the filter cap at the -12V side.And I found that the optoisolator is open.Its a pc2501 optoisolator.
Hope can help to some readers.

Noel

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]]> By: admin https://jestineyong.com/problems-in-isolator-ic/comment-page-1/#comment-4828 Thu, 04 Mar 2010 00:38:28 +0000 https://www.jestineyong.com/?p=2657#comment-4828 HI Jimmy,

Thanks for sharing this tip!

Jestine

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]]> By: admin https://jestineyong.com/problems-in-isolator-ic/comment-page-1/#comment-4827 Thu, 04 Mar 2010 00:37:20 +0000 https://www.jestineyong.com/?p=2657#comment-4827 HI Waleed,

Testing with analog meter is much accurate then using digital meter.

Jestine

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]]> By: Waleed Rishmawi https://jestineyong.com/problems-in-isolator-ic/comment-page-1/#comment-4826 Wed, 03 Mar 2010 22:47:59 +0000 https://www.jestineyong.com/?p=2657#comment-4826 can it be alos tested with a fluke digital meter or it has to be with analog meter? thanks

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]]> By: admin https://jestineyong.com/problems-in-isolator-ic/comment-page-1/#comment-4825 Wed, 03 Mar 2010 13:24:53 +0000 https://www.jestineyong.com/?p=2657#comment-4825 Hi H-O,

If the internal components are the same then you can replace it. Some optoisolators have triac or even diac inside so you must know the internal components before you replace it.

Jestine

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]]> By: H-O https://jestineyong.com/problems-in-isolator-ic/comment-page-1/#comment-4822 Wed, 03 Mar 2010 09:05:23 +0000 https://www.jestineyong.com/?p=2657#comment-4822 Hi Jestine.

What about replacement of these ICs are they all different or can they be replaced with another one, not exactly the same for testing of say a switchmode PSU?

thank you.

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]]> By: Jimmy Lane https://jestineyong.com/problems-in-isolator-ic/comment-page-1/#comment-4821 Wed, 03 Mar 2010 07:36:50 +0000 https://www.jestineyong.com/?p=2657#comment-4821 I had an unusual problem years ago in a brand new Panasonic 25" tv/vcr combo. It had a terrible sqealling sound and I found a shorted zener in the secodary side of the power supply. This diode monitors one of the source voltages and when it hits the zener voltage shorts and kills the voltage so it won't get to high. I noticed that one leg on the optoisolator was not through the pc board. After I unsoldered it I found the leg bent over and not through. Without the reference voltage from the secodary feeding info to the primary side the switching transitor turned on harder putting out to high a voltage. After remounting everything worked good. That taught me those zener diodes from from a voltage source to ground are very important and do there job when needed. Hopes this helps someone.
Jimmy Lane

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