I woke up this morning to find no humming fan noise from my PC, but the lights were still on. Now this has happened once before about a week ago. A hard boot fixed the issue THEN, and I was back in business.

This morning it made no difference so I decided I would take apart the PC and investigate. Since it's Sunday, my computer retailer won't be open. I'll have to fix this myself.

I didn't suspect the power supply, as first of all it was new last year (a big bad ass one), and started looking in the direction of the main switch on the front.

When I push this in, the fans start for about a half a second and shut back off again. When I HOLD it on, it repeats this process of trying to start, at about half-second intervals.

So at this point ... the switch seemed to be the problem.

I ripped apart the case (and with all those stupid plastic things holding the front in place it took about an hour).

Finally I got to the switch itself, and removed the decorative piece that you actually touch from the outside.

Still the problem was the same.

I tried disconnecting the leads that go to the motherboard, but with those "not in place" it doesn't get any power at all.



My next brilliant thought was that the little plastic (sold state) switch itself was dirty or broken and needed replaced.

Good news ... My old PC would have one! So I ripped that one apart and pulled out JUST the switch with the attached wires and plugged that into the motherboard of my PC.


I was surprised to see that I'm still having the same problem. I also tried reversing the leads on the motherboard in hopes it would give a "backwards" connection. (No luck with that either.)

So here's the current situation ... I have replaced the switch. But when I "power up" and hold the switch in the ON position, the fans start & stop, at about half-second intervals.

Is there a way to bypass the switch completely? Really I don't need it.

But I'm dead with no computer and can't work!

Can you help?

Ok sounds nasty!
OK Im going to list things that I would try..they are not really in any order...
What happens if you disconnect the motherboard powerlines from the powersupply then hit the switch? my guess is the same problem?
Do you have any kind of warning LEDS on the motherboard itself? some makes like ASUS have LEDS that light up to give you an error code you can find on the models pdf handbook from the site..These error reports are normally pretty vague but can help out..
Do you have extra memory in the upgrade slots? have you tried working out which is the main bank of memory and then take out the extended memory? is it the same? now try swapping the ram chips over so your testing the extended ram in the main bank slot?
Have you got a voltmeter in the house? get that and two paperclips and bend the clips around the voltmeter probes..
Unhook every connection to the Hard drives etc and then put the probes in the connectors that you unplugged..line up the black with the black ofc then use the red probe to measure the voltages on the other pins of the connector..do this while hitting the button..is there 12V and 5V present?
You say you have an old pc handy that you ripped the switch out of? how about ripping the whole psu out? and then hooking it up beside your broken pc and then replace all the connections over to the old powersupply and see what happens? this would be a sure 100% way to prove its not the powersupply at fault.

Hopefully you can get it back to life!!
IF not I think your looking at a new powersupply or maybe a new motherboard..the Hard drives and pci cards should be ok (crosses fingers)

Marky;)

I have seen this kind of problem before and recall that it's usually one of three things. The power supply (or motherboard) may be bad or the processor is the issue.

I always carry a power supply tester with me whenever I repair computers. It comes in very handy since 9 out of 10 times it will report a pretty accurate reading. If it passes that test, I would look into other issues.

When I say the processor is the issue, it doesn't necessary mean replacing it. I would remove it from the motherboard and take a look at all the pins. Make sure none of them are bent. Then reseat it back to the processor slot and make sure it's locked in properly. I would apply some thermal grease to it before mounting the heatsink/fan back on top of it.

Take a look at the motherboard also. You should be able to see small 'barrel' like connectors there. These are the capacitors. Make sure that NONE of them are looking bumpy or are leaking. They should have a flat surface on top. Otherwise, the motherboard is the source of the problem.

I tried another PSU too and the same thing with that one. (I always keep a spare since I've blown these before and they're such an easy thing to test.)

I also disconnected all drives (DVD, HDD, FD etc.) and removed the RAM.

The PSU fan tries to spin. The CPU fan tries to spin. And my 3rd cooling fan also tries to spin. And there's no visual evidence of blown caps anywhere.

I just got off the phone with my brother in law who is going to lend me a 2.6 machine to put my stuff into to get back up. Then we can trouble shoot further. He's thinking it's the motherboard. Yikes it's only 15 months old but out of warranty!

Yes there's a voltmeter here in the house.

It's fixed.

AHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH! What a relief!

It was the power supply afterall. We opened it up and it had 3 blown caps, and a ceased fan.

The reason the 2nd PS didn't work at my place was because the CPU was still hot from all my efforts to get it going.

When I ventured out in the cold to get some help with it, it properly cooled down.

While we had it apart we also removed the CPU fan and cleaned it along with the cooling fins. They were quite dirty even though it was new in the fall of '05.

Thank you for your suggestions.

just like i guess but it seems that you already solved it.. sometimes when the motherboard gets too hot, it will shutdown itself up. normally a computer will act like that on two special conditions, one is that your motherboard was busted / overheated or the power supply was overheating rapidly due to busted parts.

on problem relating to bad memory, the computer will still have a normal power flow and all fans will spin but the system board will not boot properly and will either beep or stay quite.

This post has been edited by vhortex: Feb 26 2007, 03:40 PM

I learned from this experience that if the CPU is too hot (actualy overheated) I can't trouble-shoot at all. With everything I removed or replaced it made no difference. For example, I popped out the RAM, I replaced the power supply etc. I was getting nowhere because the CPU wouldn't run.

*grin* and here I thought I was actually doing a good job trouble-shooting my problem *grin*

I also learned from this experience just how dependant I am on my PC. Likely having no PC is worse than having no car. I'm lucky in my case that my daughter and husband both have PCs so I could at least get online and check my new email and post at forums such as this one. But for about 8 to 10 hours I couldn't access the incoming mail that had arrived prior to 3:00am when the system went down. I couldn't see if there were any questions from clients (or prospects) and I had just launched a promotion 36 hours earlier. It could have been a nightmare if I was much longer without being able to see those emails. (It was just about killing me.)

A big hug and a thank you for your suggestions when you were helping me sort this out. You guys are great.

Gin

No probs Gin..were all here to help each other out and help ourselves out with one of the best hosting packages on the net there is esp now all the upgrades have been handled!
The Xisto network goes from strength to strength and our social network gets better too!

Marky;)

P.S. did the last campaign you were running work out for you?

You sould never open up a power supply. That is very dangerous as you could easily give yourself a big zap. If you suspect your power supply isn't working, let the computer sit a while (to cool down), then try another power supply.

You've got the be very stupid if you zap yourself when opening a psu . You can only do that if you touch the bottom of the PCB (the conctacts of the capacitors). But most modern motherboards tend to discharge the PSU reasonably (because of the stand-by LEDs), so there isn't too much to worry about (but you still have to be very carefull, never underestimate the power of electricity)