Odd ps problem

[dompan]

Hello i verified 4.6v on green wire at plug and if jumped the ps turns on
so i assume ps is good. so i assume problem is the board or switch. button checks out but i'm only getting 1.6v at the switch.strange.

i plug in a diff p/s and get 3.6v at switch and p/s turns on.i'm assuming the 1.6v at switch from the stock p/s is not enough to turn it on.but why am i getting only 1.6v at switch when the input is 4.7? and not with the other p/s?

does the 5v input power other things then just the switch that might be pulling too much for an aging p/s and causing it to drop to 1.6v?
thanks for any help

 

[r_manic]

What power supply are you using? I'm assuming that there may be something wrong with it.

 

[jsc]

What is the original problem that you saw?

The reason I ask is because everything you wrote is completely irrelevant to any problem you may have. Part of the problem is that you do not have a good idea of what is happening inside your PSU. You have a problem and you decided to measure stuff. So far, so good. The problem is that you don't know what you're measuring.

The main power plug has a bunch of wires. Most are either output lines carrying power or grounds (yellow - 12 volts, red - 5 volts, orange - 3.3 volts, black - ground). You have two control lines, one going into the PSU (the green wire) and one coming out of the PSU (the grey wire). The rest of the wires are relatively unimportant. BTW, the color coding is standard.

Grounding the green wire turns on the PSU. That's what the case switch does. It momentarily completes a path to ground. This should turn on the PSU. The voltage on this pin doesn't matter. It depends on the internal construction of the PSU. The only thing here that matters is that grounding this pin turns on the PSU.[/] If it doesn't, the PSU is broken.

The grey wire (called "PowerOK" or something like that) is an output that goes to a logic HIGH (about 5 volts) after all the PSU outputs stabilize. This signal tells the CPU to boot. No good signal, no boot.