W-7 will not shut down

Had a similar issue, and it was the motherboard. But, I would try another power supply before I replaced the MB.

TechnoMage2016 said:

Just when a PC power supply turns on and off is controlled by one wire, from the motherboard to the PSU. So the first thing I would try, related to the mobo, is to remove all power from the system.
Then remove the cmos battery and check its voltage. If it's below 3.0vdc, then replace it, but do not put the battery back in for at least a half hour, to give the cmos plenty of time to drop down to zero.

If your problem is truly in the motherboard, that just might fix it.

Good Luck!

Battery was something I was wondering about, but dismissed it from not understanding exactly what it does. Also, risking wearing out my welcome, When does the HDD spin up/start to run and when does the HD activity LED blink?
I have the feeling that the problem may be 'reversible' due to the fact it let me reload a fresh W-7 onto a wiped HDD- even tho it would nor restart again. [Or NOT] Will give your suggestion a shot tonight..
Thanks a million!

cornemuse said:

On the psu 24 pin power plug, there is "one" green wire to this plug. (between a bunch of black wires) Unplug everything from psu & 'jump/short' the green wire to one of the black wires. The psu should start & continue running until you disconnect the jumper.

I myself do not bother unplugging everything, I just do not want anyone blaming me for frying anything of anyone elses, , , ,

This is a good way of checking psu voltages, although under no load.

-c-

It's not that the PSU will not start- it will not stop..

bigmck said:

On the outside of the case, the back of the PSU is an on, off toggle switch. While it is running, flip it. If your PC doesn't turn off, something is really weird.

Not all power supplies have the switch, but in any event, OP already stated that removing power would, of course, shut it down!!

Battery was over 3v. Left out 3 hours and replaced- acts the same. It is an older computer used by my wife, no major loss so she gets another one. Any way to isolate if it is the PSU, MOBO or CPU? Should just toss it but I like to tinker with things in my spare time..

bigmck said:

On the outside of the case, the back of the PSU is an on, off toggle switch. While it is running, flip it. If your PC doesn't turn off, something is really weird.

The PSU toggle switch behaves exactly like unplugging the unit. ON- everything (PSU, fans and lights) run, but it will not post (present any video). Off- shuts down.

Some of the suggestions elude to the 'green wire' as being the sole connection to the MOBO. If so, it has to be a control circuit allowing the MOBO to turn the PSU off and on. Got to thinking and just unplugged the 24 pin main power plug from the MOBO and the PSU still runs until it is unplugged again. To me, that would suggest the MOBO may have dodged the bullet and the PSU took it in the shorts (no pun intended)

If the PSU output voltages are present then the control circuit from the MOBO is being negated by some sort of stuck/fried relay system within the PSU. IS that possible? If so, is the MOBO not booting because it is required for the PSU to recycle as the first step of the booting process?

Realize this is getting a little technical and probably something most do not know, but I do not want to tear down another computer to substitute a 'good' PSU so will have to buy one if what I am thinking is a possibility.

Thanks a million for any and all suggestions

idahjo said:

Some of the suggestions elude to the 'green wire' as being the sole connection to the MOBO. If so, it has to be a control circuit allowing the MOBO to turn the PSU off and on. Got to thinking and just unplugged the 24 pin main power plug from the MOBO and the PSU still runs until it is unplugged again. To me, that would suggest the MOBO may have dodged the bullet and the PSU took it in the shorts (no pun intended)

If the PSU output voltages are present then the control circuit from the MOBO is being negated by some sort of stuck/fried relay system within the PSU. IS that possible? If so, is the MOBO not booting because it is required for the PSU to recycle as the first step of the booting process?

Realize this is getting a little technical and probably something most do not know, but I do not want to tear down another computer to substitute a 'good' PSU so will have to buy one if what I am thinking is a possibility.

Thanks a million for any and all suggestions

I agree, sounds like a bad power supply.