EEVblog® Electronics Community Forum
Electronics => Repair => Topic started by: rodd on February 14, 2021, 08:33:37 pm
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I have this bronze series 650W PS from thermaltake which I am trying to repair.
When tested using one of these computer PS tester it alarms that the power good signal is not ok (HH condition).
I opened up the PS and found that the it uses a PS224 power monitor IC which is also responsible for generating this signal.
However the problem is still there after the IC was replaced.
I wonder if the problem may reside in one of the SMD capacitors (and or few resistors) that are part of this small auxiliary board.
There is a known problem on the stand by circuit of another computer PS where the glue used to fix the smd components in degrades and makes the board not work as expected.
Any other ideas?
Thanks
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The Power Good output is open drain, so it requires a pullup resistor on the motherboard or in the tester. Could it be as simple as that?
https://web.archive.org/web/20180712175702/http://silicon-touch.com:80/product/spec/Power/PS224.pdf (https://web.archive.org/web/20180712175702/http://silicon-touch.com:80/product/spec/Power/PS224.pdf)
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Thank you for your reply.
Unfortunately I can't open the link you have attached.
I think that the tester is working since it tested OK another PS.
I have to press and hold the power button of the computer to shut it down (software power off does not work).
It seems there is a problem with the power good signal of this supply.
Roger
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There is a known problem on the stand by circuit of another computer PS where the glue used to fix the smd components in degrades and makes the board not work as expected.
IMHO it's not true. It's heating the IC during its removal that revives it. And people wrongly conclude it has something to do with adhesive under it. And then it often dies again after some time, even with all of the adhesive removed.
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Thank you for your reply.
Unfortunately I can't open the link you have attached.
I think that the tester is working since it tested OK another PS.
I have to press and hold the power button of the computer to shut it down (software power off does not work).
It seems there is a problem with the power good signal of this supply.
Roger
How about attaching pull-up resistor and measuring actual voltage with multimeter?
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https://www.hardwaresecrets.com/datasheets/PS224.pdf (https://www.hardwaresecrets.com/datasheets/PS224.pdf)
put 4k7 pullup and test
I'm not really expert in windows behaviour (the OS that shuts down your pc), but software shutdown puts standby via green wire (power supply INPUT signal), pin 14 I think, and powergood signal is power source OUTPUT grey, pin8
maybe those 2 problems are just not related, focus on PG output