Mystery power-down on emachine

[rowboat]

I have an eMachines desktop I've had for three or four years. I've heard about what crap these machines are, but mine has done right well until very recently. Starting a few days ago, the machine shuts itself down suddenly and with no warning.
When it does this, the power is still on, but the screen is dead and it won't respond to the keyboard or mouse. The power light, instead of being on solidly, is blinking. I have to cycle power to get the machine to come back on.
This can happen in as little as 20 minutes after turning the power on, or the machine can run all night without issue. I can start it from a cold start (when it's been off for a day or two) and it might crash in 20 minutes. Or it could have been running all night and I'll use it for a few hours before it crashes. So I don't think it's a heat-related problem.
A call to eMachines was useless. When they heard how old this thing is, they just snorted.
Any ideas where to start?

Thanks!

 

[CCT]

Download Everest and have a look under Computer, Sensor and mark down what the temps and voltages are then watch the temps and voltages while you run an Anti-malware proggie in the background.

http://www.majorgeeks.com/download4181.html

 

[captaincranky]

It's never a bad idea to replace the PSU in an Emachine. Even in a worst case scenario where the mobo is bad, a new PSU will likely survive. And if nothing else you will have a good spare for whatever you next computer might be. Inspect the motherboard, especially around the processor for any sign of burned capacitors. The problems with Emachines mobos are not universal. They do have their share of bad issue, but quite a few decent ones as well.

Some of the problems you're describing are small quirks that I've noticed with my own machine.

1. Not recognizing the mouse on resume from standby.

2. Black screen graphics crashes. In my case that occurs once in a while, but I'm asking a lot from the onboard graphics, running a monitor with 1920 X 1200 resolution.

3. An old Windows installation or a dose of malware can also produce the symptoms you describe.

4. A blinking power light is the method Emachines notifies you the machine is in standby. Hence the string of question marks here...????

5. Obviously heat is a possibility as well. The thing here is the a machine that is good and warmed up, (but not outright overheating), will sometimes refuse to go to standby as the system tries to cool down the CPU. Fan stops, temps rise as the heatsink is no longer enjoying any airflow over it.

When was the last time you cleaned the CPU heatsink?

Get back to us, tell us what you find...

 

[rowboat]

Thanks, CCT - I'll try the Everet download. I'm not sure what it would mean if it's running hot, though. I cleaned the mobo and heatsink less than a month ago.

And Thanks, Captain Cranky. I've been reading about how bad eMachine PSUs are, and was planning on replacing this one when I can get to the store next, which should be Monday.

If I understand you correctly, the machine thinks it's gone into standby when the power light blinks. Of course, I don't expect it to go into standby when I'm in the middle of typing a sentence, and I wish there was a way of getting it out of standby short of pulling the plug, but I guess you can't have everything...

The reason I don't think it's a heat problem (and when I try Everest I may eat my words), is that the machine may crash within a few minutes of a cold start (CPU at ambient), or it may stay up all night while I'm running an anti-virus scan. It crashed four times this morning when the ambient was low, and not at all this afternoon when the ambient was much higher than I like. Unless maybe it was jsut too cold? Naah - it's not an automobile!

Thanks for your suggestions, I'll let you know what Everest has to say.

 

[captaincranky]

Intel or AMD Based Emachines.....

It would help us to know the model number of your machine. If it's an Intel board, there is a hardware monitoring program available directly from Intel called "Intel Desktop Utilities". You would probably require the "light" version, as the full version is only for use with Intel's later chipsets. This is the same as "Everest, but is Intel specific.

It is possible for the thermal compound on the heatsink to breakdown over time, so since the interior of the box is clean, if the problem turns out to be a heat issue, that could be something to consider.

If a machine is not detecting the mouse & keyboard while in S3 (standby) it makes sense that you couldn't revive it without a hard powerdown & reboot first.

Certain programs like Anti Virus scanners, won't allow a computer to go into standby while they're working, so there's no surprise there when you say it doesn't go to sleep.

Modern computers have what is called "ACPI" or "Advanced Configuration Power Interface", and part of the computer's ability to "hibernate" or "sleep" is controlled with circuitry within the PSU, which provides the "soft off" function. If this capability didn't exist, standby wouldn't be possible, and you'd need to disconnect the line current (the same as a "light swich" arrangement) to turn it off at all.

 

[rowboat]

I've had Everest running for several hours now and the CPU temperature seems to be holding steady at 46 C, which to my naive mind seems reasonable. The disks are slightly warmer at 55 C, and the mobo comes in at 77 to 80 C. The last might be a tad warm, but I really don't know what I should expect.

Of course, the blooming thing hasn't flaked in the last ten hours, either - that's probably because I've started asking you experts about it!

It's an Athlon processor, so I don't think the Intel program will help much. At this point I'm banking on the PSU. I plan on yanking it out tomorrow so I have something to compare with when I hit the shop on Monday.

 

[captaincranky]

Depending on what vintage your Emachine is, it will have a bestec PSU, either 250 or 300 watts. It is legend that the 250s are lethal to motherboards, but the much improved 300 watters are only dangerous to themselves. I would go for a 350 watt unit either Antec or Seasonic. The Antec EA-350s are allegedly made by Seasonic and are on sale at Newegg quite frequently.

This EA-430 is on sale now, but not quite at the really lowball prices at which they were selling. Still a decent buy though....http://www.newegg.com/Product/Product.aspx?Item=N82E16817371006

That's the same price as the 380 and with a 10 buck MIR. The larger PSU would be better for a graphics card upgrade, should you ever feel the need. And as I said, you could always take it with you to a new machine.