PSU overvoltage?

[captainjon]

Hi,

I've bought 2 PSU's from Ebay, one after the other as I cant get them to work on either
of my 2 systems (ASRock Alivedual eSata2 and Gigabyte EP35 DS3R). The Power
does not come on at all.

I followed instructions on this page to test it.
http://pcsupport.about.com/od/toolsofthetrade/ht/power-supply-test-multimeter.htm

Using a wire on the green (PS_ON) to GND, it turns on and I measured the voltages.

Be Quiet bqt e5

red 5.12 ok
orange 3.52 not ok (+3.135 VDC to +3.465 VDC)
yellow 12.36 ok
blue -11.66 ok
purp 5.16 ok (+5VSB)
gr 5.13 ok (PWR_ON)

LC 6550

red 5.13 ok
orange 3.37 ok
yellow 12.03 ok
blue -11.85 ok
purp 4.5 not ok (+5VSB)(+4.750 VDC to +5.250 VDC)
gray 5.13 ok (PWR_ON)

You can see that there is a voltage on each slightly out of spec. Would this be enough for the
motherboard to turn off PS_ON to the PSU, or is there another reason. Does the PSU need to be grounded
via the case, as I have the PSU next to it on the floor? Maybe something else I missed?

thanks,
Jon

- I am now aware second hand PSUs on Ebay is not a great idea.

 

[Zap]

Don't know about the Be Quiet, but AFAIK the LC is a shoddy unit. What are the rest of your parts? Particularly, what graphics card?

Has your system worked at all with any power supply?

 

[captainjon]

Both test systems already have a functioning (old) power supply, so they do work currently. Graphics cards are ...

Asrock + AGP Radeon 9700 + SATA HDD
Gigabyte + Pci express Radeon HD4750 + 2 x SATA + 2 x IDE devices

Its not turning on, I think its a more fundamental problem, but are the newer PSUs more sensitive to peripherals than older ones? The motherboard is not sending the POWER_ON signal to the Psu though. I've tested them without adding the hard discs attached, just powering the motherboard and Video controller.

 

[Emulex]

is your puresine battery backup capable of AVR? it will correct overvoltage at A/C.

Yes ground your isht. i've seen wierd things happen when folks don't ground everything. those plywood pc's are not safe.

grounding is just plain safe to do. in case of surge or whatever.

 

[captainjon]

dont know about AVR. But I've tried it with a grounding.

Does measuring the correct voltages without a load mean it should
at least turn on?

 

[BoomerD]

I can't offer any help with the ones you have, but I'm always surprised at folks who want to build a nice computer, buy quality processors, motherboards, and video cards...then try to cheap-out on the PSU...the "heart" of any computer system. A bad PSU can take out all your expensive components.

You MIGHT try asking over at http://www.jonnyguru.com/forums/
Power supplies are what they do.