Converting PC power supply Q
 

This is an atx with a on/off toggle switch,
It has a green (ps on) and a grey (power good) wire,
I connect the green to a red wire (+5v.) ...wont turn on.
I connect the grey to a red wire...wont turn on.
when I connect the green to grey it runs but the +12 v. will jump between 12.1 then down to 11.5
real sparattic. Is this pc supply shot or is there something ive overlooked ?
Ive done 3 others and havent run into this before.
Any help is appreciated.

RE: Converting PC power supply Q
 

iirc, I connected the green to a ground (black)..

a PSU needs a load to stabilize the voltage...
did you install a resistor to apply a load?

RE: Converting PC power supply Q
 

Hey exeter,
Yes, I used a resistor and that got it up to 12V.
I connected the green to red and it wouldnt come on.

RE: Converting PC power supply Q
 

The green Power_On line is an active high rail - if you meter this while the PSU is plugged in and the AC master switch is on, it will generally run between 4 and 5v DC. To power up your PSU, this line needs to be pulled low, ie. shorted to DC ground. You may either manage this via a toggle switch, or if your PSU has a master AC switch on the back, just tie the green wire to one of the DC grounds (black) and use the AC switch.

RE: Converting PC power supply Q
 

Thanks all, got it rite now, everything wired and putting out a steady 12.2 V.