Question PSU powers down immediately

[_shine]

I just got a new PSU to power my slave video cards. I was using "paper clip" method to power on PSU with a couple of video cards plugged in PCIE power connectors. Motherboard and all other stuff was powered by another PSU.
I was doing some testing and everything was working fine ( I even didn't put on any load yet ). Then I moved cables around a little bit and PSU shut down. Possibly I shorted something doing that.
Now every time I try to start my PSU it shuts down after a second or less. I tried running it with those cards, on its own with paper clip only - same thing in all cases. Tried waiting for some time to discharge capacitors, unplugging etc., didn't make any difference. Didn't test it connecting to mobo tho, but is there a point if it was working like that before ?

Is there any other test I should try ? Is there a possible bug with one of protection features ? I remember I shorted another PSU once and I had to wait like 20 minutes to get back in running, how long should I wait to be sure ?

 

[jonnyguru]

So you're saying that now when you paper clip the PSU with no load that it still doesn't power up? Even after letting it sit?

Sounds like you killed the PSU. What kind of PSU is it? Some cheaper PSUs are group regulated and if you use only one rail without a load on the others, the voltages go way out of spec and starts killing stuff... or itself.

I see guys do this with 3D Printers all the time (my kid goes to maker fairs a lot). The 3D Printer uses +12V and they buy these uber cheap PC power supply and don't have a load on the +3.3V and +5V so the actual +12V output is somewhere around +10V and eventually everything stops working.

If you're only going to use the +12V of a PSU for something like aux power for graphics cards, you really need to make sure the PSU has DC to DC for the +3.3V and +5V.

 

[_shine]

@jonnyguru I got this PSU https://www.enermax.com/home.php?fn=eng/product_a1_1_1&lv0=1&lv1=70&no=311
I had same PSU before, it worked 1.5 years on 700-800W load almost 24/7, then it died. Only difference I had that one plugged in my mobo.

When I paper clip it with no load or some small load (a couple of fans) it turns on for a short time, then powers down. Also it spins plugged fans for that time, so I assume it's not completely dead. I will wait 1 or 2 hours more, then try to boot it up again. If that doesn't help, will leave it overnight and disassemble tomorrow if that doesn't help.

 

[AllanGH]

Since you're only using the 12V, you may actually want to go with a PSU like this one:
https://www.amazon.com/product/dp/B076BKVXRR

 

[jonnyguru]

@jonnyguru I got this PSU https://www.enermax.com/home.php?fn=eng/product_a1_1_1&lv0=1&lv1=70&no=311
I had same PSU before, it worked 1.5 years on 700-800W load almost 24/7, then it died. Only difference I had that one plugged in my mobo.

When I paper clip it with no load or some small load (a couple of fans) it turns on for a short time, then powers down. Also it spins plugged fans for that time, so I assume it's not completely dead. I will wait 1 or 2 hours more, then try to boot it up again. If that doesn't help, will leave it overnight and disassemble tomorrow if that doesn't help.

A 1000W power supply should last more than 1.5 years with just an 800W load on it. Now you have a second dead one. You're not seeing a trend here?

 

[_shine]

A 1000W power supply should last more than 1.5 years with just an 800W load on it. Now you have a second dead one. You're not seeing a trend here?

This one is warranty replacement

 

[AllanGH]

No wonder PSU prices are so high...

 

[jonnyguru]

This one is warranty replacement

Well.. Keep warranty replacing them.

Or replace it and sell it and have it become someone else's problem.

Some PSUs are just prone to problems under certain conditions.