Comments on: Strange Power Supply Tester Result

By: A van Bemmelen

A van Bemmelen — Mon, 19 Apr 2021 10:37:46 +0000

PS: Later on replacing the 8pin dil SD6863 primary controller didn't make any difference in helping to fix the strange smsp problem, as I already suspected!

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By: Albert van Bemmelen

Albert van Bemmelen — Mon, 01 Mar 2021 20:07:30 +0000

In reply to Albert van Bemmelen.

But Yogesh look at this IC on Aliexpress with top marking 31AMS13 which in fact is just a CD/HEF4001 cmos chip. So maybe your marking is not the right chip marking?

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By: Albert van Bemmelen

Albert van Bemmelen — Mon, 01 Mar 2021 11:31:57 +0000

In reply to Yogesh Panchal.

I am trying to improve my successrate in fixing the more troublesome high power supplies. And hoping to at least find the reason when they do not work if they fail. And now knowing which supply tester we can trust will hopefully help. I can't tell you what kind of chips you have that you mentioned but recently noticed that a UTC7500 (in this article) and the TL494 are completely pincompatible. Jestine confirmed that they may be (completely) interchangeable.

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By: Yogesh Panchal

Yogesh Panchal — Mon, 01 Mar 2021 07:55:06 +0000

Albert,
Good attempt!
I am also working on one SMPS which gives loud Chick....Sound with visible arc/Spark between Driver TX and Main switching TX on primary side checked each components out of the Circuit on primary side didn't find any bad component having doubt about PWM 8 pin IC Marked with JD3313D and Controller 16 pin IC on secondary side M13M385 but not finding any data or detail on the web.may use parts for some another repair.

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By: Waleed Rishmawi

Waleed Rishmawi — Sun, 28 Feb 2021 19:09:26 +0000

In reply to Albert van Bemmelen.

Albert: they might be expensive there but here they are kind of cheap for such devices. They go around 80 dollars but the parts are hard to find and if I find them it would be too expensive and the customer would prefer to buy a new one. Have a blessed day.

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By: Albert van Bemmelen

Albert van Bemmelen — Sun, 28 Feb 2021 11:57:46 +0000

In reply to Lynn Blakely.

Sorry Lynn, apparently the 15W load Power supply tester board no longer can be bought. See my post to Lee that shows the seller that previously had those for sale. Maybe you can build one from the weblink I gave in the comments?

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By: Albert van Bemmelen

Albert van Bemmelen — Sun, 28 Feb 2021 06:19:37 +0000

In reply to Lee.

PS: Here we can find an example of schematic of a power supply circuit with a 115VAC/230VAC input selector switch, like the one examined in the article:
https://i.stack.imgur.com/LFdCj.png

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By: Albert van Bemmelen

Albert van Bemmelen — Sun, 28 Feb 2021 06:05:36 +0000

In reply to Albert van Bemmelen.

Here the schematic of the DIY PC desktop Power supply tester on the mentioned webpage that uses 9 (!) 10 Watt power resistors as load: https://i.imgur.com/jnNKzZ3.png
That one even may be better than the power supply tester I used with the only five 15 Watt resistor loads? After all 9 x 10 Watt is more than 5 times 15W? Anyway, good luck in building or finding one Lee!

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By: Albert van Bemmelen

Albert van Bemmelen — Sun, 28 Feb 2021 05:47:22 +0000

Found one Lee! See: https://nl.aliexpress.com/item/1720482275.html But they sadly sold out on them.

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By: Albert van Bemmelen

Albert van Bemmelen — Sun, 28 Feb 2021 05:38:36 +0000

In reply to Lee.

I bought my second PC desktop power supply tester with the 5 resistor loads a few years ago and couldn't find any seller anymore that still sells these now. Not on eBay and neither on Aliexpress or Banggood. Sorry Lee, if I do find one I'll let you know in a new comment here. But maybe you still could make one from websites like this one?: https://www.reddit.com/r/electronics/comments/cb3ok3/simple_atx_psu_tester/

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