Broken PSU?

Olaf6541 · November 2, 2021

Hi all,

I'm having troubles with a Cooler Master Masterwatt 450, so here is a little backstory about it:

- I used for my server build until I had an incident with a 12V fan header causing a short circuit on the steel pc case

- PC wouldn't turn on anymore, didn't bother to troubleshoot the psu and left it for some time thinking the psu was bricked

- After a few months, finally had the motivation to troubleshoot, pc just turned on like nothing happened, no further issues

- Shut down the server build after a few months as I wouldnt need it for a while

- Recently wanted to use it again, now again the pc doesn't want to turn on at all

I tried to hotwire the psu but it is not turning on, and I don't even measure anything on the 'green' wire (I assume I should be able to measure a 5V pulled up voltage there?). What can I do further to troubleshoot this psu?

suedseefrucht · November 2, 2021

15 minutes ago, Olaf6541 said:

I don't even measure anything on the 'green' wire

I couldn't find any cable colors in the manual. So I have no idea which cable you mean.
There are 2 options:

1. You have the knowledge and the tools to repair a power supply.

Take just the power supply (without the PC), read the manual,

Use a piece of wire to connect 2 pins to turn on the power supply.
Then measure all the voltages.

2. Just get a new one.

Olaf6541 · November 2, 2021

1 minute ago, suedseefrucht said:

I couldn't find any cable colors in the manual. So I have no idea which cable you mean.
There are 2 options:

1. You have the knowledge and the tools to repair a power supply.

Take just the power supply (without the PC), read the manual,

Use a piece of wire to connect 2 pins to turn on the power supply.
Then measure all the voltages.

2. Just get a new one.

There are indeed no colors (only black) i'm talking about the standby voltage wire (ps-on) that you would normally short with the power button to start the pc.

atx psu pinout

As I said I already tried to connect the green pin with ground but nothing happened, then I used a multimeter and didn't measure any voltage...