Computer won't POST

[Chrispr]

Ok, I have been dealing with computer assembly now for a few years and I have become the local resident expert among my friends when something goes wrong. I have always been able to fix any computer I got up until now. I received an eMachine that would not post. Immediately I assumed it was the motherboard so I swapped out the MB and there was nothing. I thought it might have been the RAM, so I put a new stick of DDR in just for the heck of it, still nothing. Obviously when the computer tries to boot without RAM, the BIOS will usually go crazy with beeps giving me error codes, but I didn't get any life at all. Tried to boot with a different hard drive, CD-ROM, floppy, and just the very basics, i.e. motherboard, CPU, keyboard, RAM and nothing else.

I then figured it must be the PSU, so I switched that and nothing happened. The very last thing it could be was the CPU, since there was no life in the computer. I switched the CPU with 2 other amd athalon XP's and still nothing. I left the new MB in with these processors and still nothing. I have no idea what could be wrong, the motherboard was brand new, and I know for a fact the CPU's were working in ohter systems. I guess the only thing I haven't tried is using another case. Any ideas what could be going on here?

 

[richcleverley]

Does the video card seat properly in the case/MB. I know sometimes my pc does this, and I have to reseat the AGP card to get to work. Also sometimes if I have a lot of usb devices connected I have to boot without them then replug them. It then works fine and boots next time. Possibly a power issue there.

Richard

 

[Chrispr]

It's an eMachine so it has onboard video, as well I made sure that both the mouse and keyboard are PS/2 to avoid any issues with USB. Not sure what it could be at this point.

 

[G0AOZ]

You need to go to a working PC and then swap over parts one by one from the "dead" eMachine. You will then have checked each individual component still works ok. Wouldn't hurt to run some tests on the memory.

Try clearing CMOS, either using jumper if provided, or pulling battery out for a while. Remember that some components can get a small static charge which may prevent them from working. Once dissipated, the item then works normally again.

You could also try plugging a video card into the eMachine mobo. It may have jumpers to disable on-board video, or switch automatically.

Check that the eMachine's momentary front panel ON/OFF switch is working correctly by tracing the wires to the mobo. Lift off the connector and try shorting the mobo pins with a screwdriver blade or similar.

ROGER - G0AOZ.

 

[paparazi]

Chrispr
If you look at this logically, you have changed everything so the problem know longer lies with the eMachine, obviously one or more of the new components is faulty also.

I work in a PC custom build and repair shop, we see dozens of faulty eMachines, typically their power supplies fail and in the process the motherboard is damaged by the resulting spike (Hard drives and CDrom devices can also be damaged and as a result be a dead short to ground when tested)

What you need to do is work out the case, Start with just the motherboard/CPU with cooler/ram and PSU, not the hard drive or CDrom (obviously monitor connected) place the motherboard on it's own empty box.

Clear the cmos

Momentarily touch the pwr (power header pins) with a small flat blade screw driver
Now if you don't see a post you haven't got too many components to elliminate in the diagnostic process.

Martin

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Participate and help others.

 

[Chrispr]

I agree that the problem lies with faulty hardware. After testing the RAM, CPU, PSU, and MB together outside the machine, it still would not post. I tried the RAM in other computers and it works fine, I tried different power supplies and they worked as well. I also tried 3 different processors in the MB and none of them worked. Statistically speaking, at least one of 3 processor should have worked in the MB, so I have therefore concluded the MB must be the faulty part. I'm going to RMA it to the place I bought it from and hopefully they will cover it. Thanks for the help.