DIY PC Bench Supply Troubleshooting

[Muneeb]

So I recently Bought some led strips to use as the primary light source in my room. And it won't work on 1-2 amp adapter as it would consume upwards of 100 watts, so I google things and decide to run it off a pc supply. So I do the usual green wire to ground wire jump/short, pull out a couple of yellow 12V and Ground wires and hook them up to led strip, and it works sometimes and sometimes comes on for just half a second and the rest of the times it doesn't start at all.

The power supply is new but fairly basic, puts out a decent 310 watts and 20 amps on the 12v rail. Just cannot figure out what could be tripping it. Also, the supply in my home is 252 volts,  I don't know if that's the cause because my pc runs fine but it may be because it has a powerful Corsair PSU.

It would be really helpful if you guys can figure out a solution.

thank you
Muneeb
 

[Kleinstein]

Some supplies need a certain minium load on the 5 V / 3.3 V rail to work, especially with heavy load on the 12 V. Without the 5 V might go too high and a protection circuit can trigger.

[Muneeb]

Some supplies need a certain minimum load on the 5 V / 3.3 V rail to work, especially with a heavy load on the 12 V. Without the 5 V might go too high and a protection circuit can trigger.

Like maybe a Phantom load on the 5-volt rail?

[hugo]

Just add a real load to the 5 V output rail and see if it works.

[John B]

It could be tripping the short circuit protection. Without load testing the supply, I wouldn't trust the rated figures. For example I have tried a similar thing with a supply rated for 20A on the 12V rail. Even a 1 ohm load trips the short circuit protection. You'd need to consult the specifications to see if the rated current is a genuine constant figure.