Power supply

[lofty531]

I went 2 switch on my pc and nothing happened,it was dead.I replaced the atx power supply,It booted and ran fine 4 one session,switched off as usual,went 2 switch it back on,nothing,dead,can anyone help please.
Thanks in advance.Ian.

[NDD]

Check the CMOS battery on your motherboard, replace if needed ...

Best Regards ...

[Bovon]

It could be the on-off switch on the front of the computer. This is a momentary switch, and only makes contact while holding the button in. To turn on an ATX psu, it applies +5 volts to the psu (yes, the power supply is always energised with a second 5 volt part, that runs all of the time the supply is connected to an outlet)

It takes 0 volts to turn it off (mobo ground) Try this if you can. Take the cover off...try turning it on with the switch several times, sorta wiggle the switch button around to see if it will make contact. If nothing happens, pull the cable off of the mobo where the switch connects, and short the two pins with a small screwdriver or something simular. If it now comes on...your switch has gone bad. If it still does not come on...the problem may be with the circuit that turns it on, either thru the mobo. or something is killing the 5 volt supply that runs continusly.