Stupid quick question - Will a PS power on if not plugged into a motherboard?

DietDrThunder

Platinum Member
Apr 6, 2001
2,262
326
126
The reason I'm asking is because I have a small case and I don't want to disassemble everything if it doesn't work. Or is this a bad idea?
 

CurseTheSky

Diamond Member
Oct 21, 2006
5,401
2
0
No, but you can short two of the pins in the main (24-pin) connector, which will allow it to start. Google for which pins you need to short.
 

Auric

Diamond Member
Oct 11, 1999
9,591
2
71
I recently tried this with two units and neither ran yet both did when connected to the mobo. I tried adding a fan for a wee load too. So not sure wha' happen other than perchance needing more time to charge.
 

Meghan54

Lifer
Oct 18, 2009
11,684
5,228
136
I recently tried this with two units and neither ran yet both did when connected to the mobo. I tried adding a fan for a wee load too. So not sure wha' happen other than perchance needing more time to charge.


There is no charge time involved....either it comes on or not.

But, if they didn't start, look at the label on the power supplies sides. Are there listed minimum loads that have to be present? If so, then you MUST present the power supply with that minimum load....and fans typically don't present much of a load at all.

Older power supplies, or older power supply designs, can have a 1A minimum on every rail, and a fan won't cut that. Several fans may.....my S-Flex fans only have a 0.25A draw, so it'd take 4 to give a 1A load on the +12V rail, and that's only that one rail, not including any minimum necessary on the +3.3V or +5V rails.