Is my computer killing my power supplies?

[cbuchach]

I need to try to explain the strange issues with my machine. I have an Asus P5Q-E with and overclocked Q6600 (413*8 at 1.500V) that has been working well for some time (8+ months). I normally leave my machine on 24/7 but went on a long vacation and turned the machine off. I came back from the 11 day vacation and turned on my machine and nothing. The MB lights were on and tried pushing the onboard power and reset switches with nothing. I tried a few things but eventually ended up trying a different PS (only for a few seconds to see the fans spin up) and the machine turned right on. So my power supply was a few years old and I figured it had died.

So my new replacement power supply arrives a few days later (a Fortron source 700W) and I plug it in and the machine boots right up. I had cleared the BIOS so needed to re enter all my settings and then got into windows with no problem. I then went about resetting my FSB speeds and voltages in the BIOS and booted into Memtest to ensure stability. I came back and the screen was blank, the machine was powered down but there were lights on my keyboard. So I thought maybe the overclock was bad and restarted with nothing. I became worried and again cleared the BIOS and pushed the power button-----nothing-----I sat starting to get concerned and out of the blue the machine turns on---what the hell??

So I got back into windows and started using the machine. I then rebooted and made what may have been the mistake of re-entering my overlclock settings and restarting. The machine again booted into windows. I went away for a while (20 minutes) and came back and the machine was off.

I since have been unable to get the machine to start with the new power supply. I did have an older power supply available and have since connected that for a brief second and it still works. With the seemingly other two dead power supplies the motherboard lights are on when it si connected but the machine absolutely does not turn on, the fans don't spin and nothing happens.

So it seems to me that my previsouly stable computer with absolutely no issues has now apparently started destroying now two power supplies? Does anyone have any idea what is going on? I am assuming this must be a motherboard issue--but why and why now? I am thouroughly perplexed and what appreciate any possible help.

 

[Slugbait]

It sounds like you're shorting out.

Pull the mobo and verify the standoffs, each one should have a corresponding screw hole. Also keep in mind that if you have an ATX/BTX case, there is one spot on the mobo tray that needs to be covered to prevent shorting out an ATX mobo (such as it is with the Armor). If the cover for that section of the mobo meant for BTX has fallen off, there's the culprit.

The PSUs may not be dead at all. Instead, the fuses may have blown to save them.

While the mobo is out, this would be a good time to clean and re-apply the thermal compound for your HSF.

 

[Blain]

What would you give for a $20 power supply tester?
What memory were you testing when Memtest shot craps?

 

[cbuchach]

Originally posted by: Slugbait
It sounds like you're shorting out.

Pull the mobo and verify the standoffs, each one should have a corresponding screw hole. Also keep in mind that if you have an ATX/BTX case, there is one spot on the mobo tray that needs to be covered to prevent shorting out an ATX mobo (such as it is with the Armor). If the cover for that section of the mobo meant for BTX has fallen off, there's the culprit.

The PSUs may not be dead at all. Instead, the fuses may have blown to save them.

While the mobo is out, this would be a good time to clean and re-apply the thermal compound for your HSF.

I wondered if it was a shorting issue though seems to be manifesting a bit strange. The system was working perfectly for 8 months and was left off for 11 days when the issue came up and the MB is properly seated with all the screws in place. I will end up pulling the board and look for anything, but am not going to attach another PS to it even on the workbench.

It must also be the case that not all the rails have shorted, as the MB lights still turn on. Is it possible that a short has developed along one of the rails within the MB circuitry? Since I leave the system on 24/7 it obviously was used to a certain operating temperature, then turing it off would have cooled it down potentially cracking a trace or something? I don't know.

 

[cbuchach]

Originally posted by: Blain
What would you give for a $20 power supply tester?
What memory were you testing when Memtest shot craps?

Well, the initially issue occured after the system had been sitting off for 11 days and I have of course tried powering on the system with no memory installed and absolutely nothing happened (the system should power up with no memory installed and then give a beep error code).

 

[In2Photos]

Plugged into a UPS? Try going straight into the wall and see what happens. Could be a bad battery in the UPS.

 

[cbuchach]

Originally posted by: In2Photos
Plugged into a UPS? Try going straight into the wall and see what happens. Could be a bad battery in the UPS.

No UPS. And again, after the MB apparently kills the power supply, plugging a different PS does work and the fans spin up (though I now only leave it on for a second or two because two dead expensive power supplies is enough).

Any other ideas or options? I am going to pull the MB from the case and try it on the bench to try to exclude the small possibility of a case short.

 

[In2Photos]

Originally posted by: cbuchach

Originally posted by: In2Photos
Plugged into a UPS? Try going straight into the wall and see what happens. Could be a bad battery in the UPS.

No UPS. And again, after the MB apparently kills the power supply, plugging a different PS does work and the fans spin up (though I now only leave it on for a second or two because two dead expensive power supplies is enough).

My thought about a UPS was that when you are removing and reinstalling the PSU you are opening the circuit and allowing the UPS to reset. Since you don't have one, this can't be it!

Good luck!

 

[cbuchach]

Any other ideas as I am getting to the point where I am will RMA the 8 month old motherboard to Asus. I can't see myself plugging another powersupply into the MB for fear of ruining a third expensive powersupply.

Does anyone have experience reviving a dead powersupply namely a 620W Enermax PSU? I am thinking about searching for a possible blown fuse to replace.

 

[Slugbait]

Originally posted by: cbuchach
Does anyone have experience reviving a dead powersupply namely a 620W Enermax PSU? I am thinking about searching for a possible blown fuse to replace.

I once revived a 450W Enermax PSU by replacing a definitely blown fuse. It lasted another year before it finally bought the farm. Just open, pull, replace.

 

[cbuchach]

Originally posted by: Slugbait

Originally posted by: cbuchach
Does anyone have experience reviving a dead powersupply namely a 620W Enermax PSU? I am thinking about searching for a possible blown fuse to replace.

I once revived a 450W Enermax PSU by replacing a definitely blown fuse. It lasted another year before it finally bought the farm. Just open, pull, replace.

That's good news as the first power supply was an Enermax and hopefully it has a non soldered in fuse.

Oh, and what type of fuse will I need and where would be a good place to get it?

 

[cbuchach]

Originally posted by: cbuchach

Originally posted by: Slugbait

Originally posted by: cbuchach
Does anyone have experience reviving a dead powersupply namely a 620W Enermax PSU? I am thinking about searching for a possible blown fuse to replace.

I once revived a 450W Enermax PSU by replacing a definitely blown fuse. It lasted another year before it finally bought the farm. Just open, pull, replace.

That's good news as the first power supply was an Enermax and hopefully it has a non soldered in fuse.

Oh, and what type of fuse will I need and where would be a good place to get it?

Well I checked at RadioShack and they didn't have any of the high amperage fuses but the fuse was tested and it si still good, so it must be something with the PSU cicuitry that is the issue.