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allen_kcCard
09-09-2008, 12:08 PM
I'm trying to figure out what is going on with my main home pc. It had been working great for years now, but just last week when the power blinked in some storms now it won't start up.

In trying to isolate what the problem is, I've found that if any of the power connections are connected to a hard drive, the system will start to power up for about half a second and then shut off, and then won't even respond to a power on until I turn off the power supply for a few seconds or unplug it for a bit. I can have the IDE cable plugged in to the hard drive, and the same power connectors can be plugged into the cd rom/dvd and it will boot up, as long as the power isn't to a hard drive.

I tried another old hard drive I had around that I know doesn't work, but when I worked with it last it would let the computer boot up, it just couldn't read from the disks, but when I plugged it in this time it behaved just like the other one.

The same main hard drive works great when I put it into an external enclosure and used it on this laptop.


So, I am wondering it if could possibly be the power supply? Or motherboard? It is odd on what is happening. There was a lot of lightning when the power blinked, but the computer was plugged into a surge protector, so I don't think it would have damaged anything. I also tried letting the computer get up and running without the hard drive power plugged in, and then plugging it in when it was up, and it immediatley shuts off when that is done as well.

The common factor on everything is any hard drive plugged into any of the 4 pin power connectors out of the power supply...when those are plugged into a hard drive, immediate shutdown.

Fish
09-09-2008, 02:44 PM
Definitely sounds like the power supply. If you have a voltmeter, you could check the voltages, and it would tell you for sure. It sounds like the PS isn't supplying enough juice when powering the HD as well as the rest of the system. You could boot into the BIOS without the HD connected and see if your BIOS has voltage readings there as well. Some BIOSes will tell you how close you're PS is supplying 12V, 5V, etc.

Surge protectors are never ever 100% reliable.

If you have a working HD, I'd try that too. Just to see if it would boot with the HD attached without powering off.

allen_kcCard
09-09-2008, 04:30 PM
Yup, it is the power supply. I took a PS from another computer and hooked it up and everything booted up. Thanks.

DaFace
09-09-2008, 04:32 PM
Yep - sounds like a power supply to me. Not that you should abuse return policies, but if you buy one from a retail store and it doesn't fix your problem, most will let you take it back. Just make sure you read the return policy before assuming you can.

DaFace
09-09-2008, 04:33 PM
Yup, it is the power supply. I took a PS from another computer and hooked it up and everything booted up. Thanks.

Oh. Well good then. Guess I'm a little slow today. :sulk:

kcvet
09-09-2008, 04:42 PM
I'm trying to figure out what is going on with my main home pc. It had been working great for years now, but just last week when the power blinked in some storms now it won't start up.

In trying to isolate what the problem is, I've found that if any of the power connections are connected to a hard drive, the system will start to power up for about half a second and then shut off, and then won't even respond to a power on until I turn off the power supply for a few seconds or unplug it for a bit. I can have the IDE cable plugged in to the hard drive, and the same power connectors can be plugged into the cd rom/dvd and it will boot up, as long as the power isn't to a hard drive.

I tried another old hard drive I had around that I know doesn't work, but when I worked with it last it would let the computer boot up, it just couldn't read from the disks, but when I plugged it in this time it behaved just like the other one.

The same main hard drive works great when I put it into an external enclosure and used it on this laptop.


So, I am wondering it if could possibly be the power supply? Or motherboard? It is odd on what is happening. There was a lot of lightning when the power blinked, but the computer was plugged into a surge protector, so I don't think it would have damaged anything. I also tried letting the computer get up and running without the hard drive power plugged in, and then plugging it in when it was up, and it immediatley shuts off when that is done as well.

The common factor on everything is any hard drive plugged into any of the 4 pin power connectors out of the power supply...when those are plugged into a hard drive, immediate shutdown.

probably power supply. good guess but not the only one. you can gamble and replace it yourself. their easy to change out but big $$$$ so its a gamble. either this or off to the shop. lightning strikes can total them out.