I am attempting to fix a PC switching power supply that does not supply 5v to the motherboard power-on header pin, I'm only getting 2.5v in my bench test.
The green lead from the atx connector goes to the PS and into IC wt7525. This must be responsible in switching the 5v to the power-on tactile switch when powered off. I tried to trace the green wire into the circuit, but got no further than that IC
I replaced a bursted 1500 uf 6v cap with one from a scraped moboard. Not sure if that was causing the faulty voltage, but hope that does the trick.
We have a CentOS server that has been hanging up a lot lately, requiring a reboot. we cannot SSH into the box when it hangs. TOP commands shows me 270+ apache tasks, when there are usually 20-30 at any given time. netstat -a shows all kinds of SYN_SENT responses. Are we under SYN Flooding Attack or what is going on here?
I might have misdiagnosed this computer. The box would not power on. I jumped the power supply and the PS switches on, all rails have proper voltage. I shorted the power on pins on mobo, nothing. I get 1.7v to the header pin, that seems normal. So I order a new mobo and nothing! Good lawd. Gonna try a diff ps
Turned out the be the PS after all. The power switch pin needs 3.3 v and was only getting 1.7 v. I am going to open the PS and see if I can resolve the issue with my soldering iron, I suspect a bad transistor.