Power supply or Motherboard failure?

[ScottLovesDogs]

Am helping a friend, who is 82, with his out-of-warranty eMachines computer.

Back in Jan., just before the extended warranty expired, the warranty company replaced the motherboard and power supply. The machine just completely failed again this month. No more warranty.

Symptoms:
No boot, no nothing. Period.

I checked the PS voltages with a HP digital multimeter and they all seem fine. I forgot to check the "DC okay" line, however.

When the 20-pin power connector is unplugged from the motherboard, or the IDE cable is disconnected from the hard drive, the hard drive will spin up when the power-on pins are jumpered and the ps is forced on. But, if the HD is connected to the motherboard and the motherboard is receiving power, no go for the HD. Interesting.

Also, the CPU fan does not spin up no matter what (is an old AMD machine). And, if I wiggle the 20-pin ps connector to the motherboard gently the ps would whine a little, on and off, as I jiggled.

I am leaning toward thinking that the MB is shot.

Since Charley prefers this computer to his new, Vista based eMachines computer, he would like it repaired. But I don't want to just go in and replace the MB without being fairly certain that it is the problem.

I also can't hook it up to my nice, nifty PC P&C Silencer, because the connectors won't fit his MB.

Do any of you have any troubleshooting suggestions?

[unfaithfulsfan]

When the 20-pin power connector is unplugged from the motherboard, or the IDE cable is disconnected from the hard drive, the hard drive will spin up when the power-on pins are jumpered and the ps is forced on. But, if the HD is connected to the motherboard and the motherboard is receiving power, no go for the HD. Interesting.

Also, the CPU fan does not spin up no matter what (is an old AMD machine). And, if I wiggle the 20-pin ps connector to the motherboard gently the ps would whine a little, on and off, as I jiggled.

I am leaning toward thinking that the MB is shot.

Sounds like the mobo, all right. No old spare psu lying around just to swap to make sure?

[ScottLovesDogs]

Nope, no spare old psu. Well, a really old, pre-ATX but proto-ATX one that might work, but long ago, I hacked up the connectors to work on an old AT style board.

But it really does seem like the MB that was put in back in January was bad, doesn't it.

I can't wait to see how much eMachines/Gateway will ask for a replacement. Probably a fortune. Will likely go generic, like Gigabyte or whomever, but then I have to replace his eMachines-specific install of Windows XP with an off the shelf, generic install.

[martini161]

sounds more like a psu problem to me. you are probably making the common mistake of checking the voltages unloaded. these readings will be inacurate. and even if they are accurate, just having correct voltages doesnt mean the powersupply is in working order. what kind of multi meter do you have? could you post a link to a product page of it?

[Mumm]

In the shop I've seen tons of these eMachines come in with this same issue. 90% of the time it is due to the cheap power supply they put in them. When they get a good spike or undervoltage they crap out and take the mobo along with them. Not much you can do about it but replace them both with QUALITY parts. And then place the computer on a good UPS.

In short both are probably shot. Either way one could take out ther other and there really isn't a very cost effective method I've seen that would tell you exactly where the issue stared from.

Dont bother with a Gateway replacement part if the case will take a standard ATX Mobo and PSU. Since he has no warranty left anyway you may aswell use good parts. This is so common we stock mini atx Mobos and PSUs just for eMachines.

[Sporg]

If it were me I'd look for popped caps on the motherboard and also "borrow" a PSU from a working system. Although if you wiggle the connector and get some juicy juice that way the caps might not be it.

[ScottLovesDogs]

Martini, I checked the voltages both without a load, and with the MB and hard drive plugged in. The meter is a Hewlett-Packard E2378A.

I'm may start a new thread about the problem here, because it goes way beyond how to fix this old computer. The main problem is that Charley loves his old XP machine, the one that is broken, and hates his new Vista machine. He uses AOL, and the new machine has AOL 9.0 on it, which, along with Vista makes is so damn slow that you'd never believe it. Further, he installed Norton AV on the Vista machine and now has, I think, multiple firewalls running that result in roughly half of his attempts to get online being killed with a "Navigation Action Cancelled" message from the friggin' AOL software. Even worse, the poor guy has dial-up where he lives. No DSL there yet.

And, while typing the above, a brainstrom occurs: Since both are eMachines computers, and should have at least some similarities in the BIOS signatures (which the eMachines specific version of Windows will look for), just pull the much-beloved XP hard drive out and see if it will boot up in the new machine. What do you think?

[Sparky]

Might be worth a try, you've got nothing to lose. The Windows activation may kick in telling you it noticed some hardware changes and make you call India for reactivation.

[tekgek]

You could take the hard drive, build an new machine for him, use the Ultimate Boot CD (http://www.ultimatebootcd.com/) to make the hard drive non bootable in the new machine, and put a new copy of XP on another hard drive. To me, it seems the best way to go. That way, once the new hard drive is in the new computer, and is not the main bootable drive, then he can just access any of his old files.

Just an idea,
Tekgek