View Full Version : dead psu, high-pitched whine, 5170

December 29th, 2013, 12:41 PM
It seems my AT's psu is sick, one day it failed to turn on normally and instead just made a high-pitched whining noise(noise is from psu not mobo). This was intermittant at first, if I turned it off and let it sit for awhile, it would sometimes turn on normally. however it is totally dead now, just whining, no fan no nothing. The motherboard is good, have been running it on another psu. Just wonderig if this has a known fix or how to trouble-shoot? I already have he psu case open for repair. Thanks guys.

December 29th, 2013, 04:45 PM
First, the obligatory warnings, in case you are unaware of the hardards of working in a power supply:
* The obvious hardard of mains voltage (wall power, line power, AC power, ...)
* Some of the large capacitors can hold hardardous charge long after mains voltage has been disconnected from the power supply

If not are not exerienced, then I suggest that you not work on the power supply until at least half an hour has passed since mains power was last applied to it. Just playing safe.

Presumably, you have done a very good visual inspection (including solder joints).

In my experience of switch-mode power supplies, I have seen the described symptom often caused by the slow deterioration of a small value electrolytic capacitor. As the capacitor's state worsens, the symptom worsens.