powersupply noisey fan after clean up?

[newtoCaps101]

hi, i have a silverstone 600w psu, about a year old. I recently opened it up, removed the fan and cleaned everything up only to find that the 120mm fan is now making considerable amount of noise, as if its running at full speed. I have never noticed this before but its very annoying. The psu says it has fan sensor control so the only explanation I can think of is maybe its sensor has gone bad now causing it to run at full speed?

what should i do? any way to fix this?

[ratdude747]

Re: powersupply noisey fan after clean up?

here is what you can do:

take the cover off the unit but leave the fan connected if it is a lid mounted fan. if it not a lid mounted fan, then remove the fan but leave it plugged in. next, find on the fan where the wires are soldered to the little circuit board (you may need to peel a small amount of the sticker up to get to it). connect power to the unit and on the atx plug, short the green wire to ground with a jumper. this will turn on the psu and start the fan. use a multimeter between the red and black wires on the fan's PCB and see what you get.

a word of caution, when the cover is off a live PSU, you need to wear shoes and avoid touching the heat sinks inside the PSU. the primary one has 120vac (240 in some countries) at it and if you touch that, especially barefoot on a metal or concrete floor, you will get a nasty shock... safety glasses are also recommended.


anyway, post what you get. this is the voltage the presumably 12v fan is running on.

[mathog]

Re: powersupply noisey fan after clean up?

The psu says it has fan sensor control so the only explanation I can think of is maybe its sensor has gone bad now causing it to run at full speed?

Inspect the fan header and plug carefully. If the speed sensor pin is not making a good electrical connection you might see this. It is a power supply, so take the appropriate safety precautions.

If it is a standard 12V 3 pin plug you can test that the sensor line is working properly by removing the fan from the PSU and plugging it into a 3 pin header on a motherboard that supports fan speed monitoring in the BIOS.

[999999999]

Re: powersupply noisey fan after clean up?

See if it is really running at high RPM or just noisy because the bearing ran dry or fan shaft washer came off and now has play in it?

At no load or very low load condition, measure the voltage at the fan connector. Check the fan label to determine bearing type. If it's an ADDA fan see this:
https://cdn.badcaps-static.com/pdfs/...174352e222.pdf

If it has a "hypro" or "S" (sleeve) bearing, pull the sticker back, pull the plug out and put a couple drops of thick oil in, turn the blades by hand a few revs, and put plug and sticker back on.

Is it possible you had cleaned it with liquid and that created a flux solution that shorted the fan control circuit (could remain shorted even after it dried as the flux can make a metallic conductive pool of solution that concentrates as it dries).

I don't know the sensor circuit in that PSU, but if it has a thermistor and transistor and you caused ESD during cleaning, I'd replace the transistor with any having roughly same spec (need not be exact same, probably 1/3rd of all 20 cent transistors you can find would work once you know current, voltage, PNP vs NPN type, etc).

[newtoCaps101]

Re: powersupply noisey fan after clean up?

thanks everyone

I replaced the fan