System energizes, cpu fan spins, no display

ramseyrt

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Hello,

I have an e-machine T2984 that died recently. I simply turned the system off three weeks ago and it never turned on again. Looking inside the case, the motherboard shows a lit green led but the system doesn’t energize. Looking on the web, this is a popular problem with this model of system. Other owners attributed this problem to a bad motherboard. I tested by power supply by shorting the green power connector wire to ground and the power supply fan spins and the CDROM and HD energize. I suspect that I have a good power supply. So, I replaced my mobo with a Biostar P4M80-M4. This board should be a drop-in replacement for my previous board.

After replacing the mobo and energizing the system the CPU and case fans come on but I get no display. I have to hold the power button in for two or three seconds to get the system to power back down. I replaced the CPU (3Ghz Celeron) with another CPU (3Ghz P4) with the same results. I also tried different RAM (2 sticks of 512Mb PC-2700) and installed a 3rd party video card (PCI GeForce 6200 and PCI ATI Rage 128). All tests result in spinning fans and no display.

So, I replaced the Biostart mobo with another of the same model. This mobo is having the exact same problem. Again, I performed all of the same testing; replacing the cpu, replacing and moving memory, and installing a 3rd party video card.

Again, to rule out the power supply I tested it by shorting the green power connector wire to ground. The power supply fan does spin up and the CDROM and HD energize. I don't have another system to test the power supply in but I suspect that it's in good condition.

I've been double checking that the 20-Pin and 4-Pin cables are connected to the motherboard and that the CPU and case fans are plugged in. When swapping out the CPUs I make extra sure that the CPU is seated correctly and that there's a proper amount of thermal paste between the CPU and heatsync.

What am I missing? I find it highly unlikely that both CPUs are bad, both motherboards are bad, both video cards are bad, or that both DIMMs are bad. I've tried resetting the BIOS jumper on both boards and I've re-installed both boards in the case to make sure I didn't short it out.

I could really use a hand.

Thanks in advance,

Rob
 

americanbrian

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It could be a fault in the ATX connector or the loom from the PSU. You have said yourself that its unlikely that that both of everything is faulty.

Have you tried a different monitor? If you have narrowed it down this far you NEED to try a different PSU. Your test regime for it doesn't sound conclusive.
 

ramseyrt

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So, I bought a new power supply today, installed it in the case and I'm having the same issue. So, I took everything out of the case and started my testing on a piece of particle board. I know I don’t have the ideal ESD environment but I’m really trying to touch the power supply frequently and wood doesn’t conduct. I don’t have the luxury of having a full ESD bench at home : )

The only components I’m working with are the mobo, CPU, one stick of RAM, and the new power supply. I tried both CPUs in the Biostar mobo with the new power supply and I also tried both pieces of RAM. Every test results in the same spinning fan condition without a BIOS screen.

Out of curiosity, I tried these same tests with my original E-Machine mobo. It never energizes in any way other then the green led on the mobo. It must be toast.

So, I've tried two of everything; two CPUs, two motherboards, two pieces of RAM, and two power supplies. So two of something I’m using must be bad. What kind of hardware failure would cause my symptom? I'm going to try and get another CPU and piece of RAM to test with but it might take me a day or two.

I have two CRTs and two LCDs that I’ve been switching back and forth with. All four displays work on the other two working computers I have. I’m using a CRT for most of my testing if that’s of any consequence.

Again, any help is appreciated,

Rob
 

ramseyrt

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My tests have followed this pattern
Two Weeks ago…
Biostar MOBO #1 - Celeron 3Ghz CPU - DIMMs #1&#2 - Original PSU
Biostar MOBO #1 - Celeron 3Ghz CPU - DIMMs #1&#2 - Original PSU - GeForce 6200 PCI
Biostar MOBO #1 - Celeron 3Ghz CPU - DIMM #1 - Original PSU
Biostar MOBO #1 - Celeron 3Ghz CPU - DIMM #1 - Original PSU - GeForce 6200 PCI
Biostar MOBO #1 - Celeron 3Ghz CPU - DIMM #2- Original PSU
Biostar MOBO #1 - Celeron 3Ghz CPU - DIMM #2 - Original PSU - GeForce 6200 PCI

Biostar MOBO #1 - P4 3Ghz CPU - DIMMs #1&#2 - Original PSU
Biostar MOBO #1 - P4 3Ghz CPU - DIMMs #1&#2 - Original PSU - GeForce 6200 PCI
Biostar MOBO #1 - P4 3Ghz CPU - DIMM #1 - Original PSU
Biostar MOBO #1 - P4 3Ghz CPU - DIMM #1 - Original PSU - GeForce 6200 PCI
Biostar MOBO #1 - P4 3Ghz CPU - DIMM #2- Original PSU
Biostar MOBO #1 - P4 3Ghz CPU - DIMM #2 - Original PSU - GeForce 6200 PCI
I sent the Biostar mobo back to the vendor as DOA after all of the tests above failed.
Two Days ago I got another mobo from eBay…
Biostar MOBO #2 - Celeron 3Ghz CPU - DIMMs #1&#2 - Original PSU
Biostar MOBO #2 - Celeron 3Ghz CPU - DIMMs #1&#2 - Original PSU - GeForce 6200 PCI
Biostar MOBO #2 - Celeron 3Ghz CPU - DIMM #1 - Original PSU
Biostar MOBO #2 - Celeron 3Ghz CPU - DIMM #1 - Original PSU - GeForce 6200 PCI
Biostar MOBO #2 - Celeron 3Ghz CPU - DIMM #2- Original PSU
Biostar MOBO #2 - Celeron 3Ghz CPU - DIMM #2 - Original PSU - GeForce 6200 PCI

Biostar MOBO #2 - P4 3Ghz CPU - DIMMs #1&#2 - Original PSU
Biostar MOBO #2 - P4 3Ghz CPU - DIMMs #1&#2 - Original PSU - GeForce 6200 PCI
Biostar MOBO #2 - P4 3Ghz CPU - DIMM #1 - Original PSU
Biostar MOBO #2 - P4 3Ghz CPU - DIMM #1 - Original PSU - GeForce 6200 PCI
Biostar MOBO #2 - P4 3Ghz CPU - DIMM #2- Original PSU
Biostar MOBO #2 - P4 3Ghz CPU - DIMM #2 - Original PSU - GeForce 6200 PCI
Today’s testing…
Biostar MOBO #2 - Celeron 3Ghz CPU - DIMM #1 - New PSU
Biostar MOBO #2 - Celeron 3Ghz CPU - DIMM #2- New PSU

Biostar MOBO #2 - P4 3Ghz CPU - DIMM #1 - New PSU
Biostar MOBO #2 - P4 3Ghz CPU - DIMM #2- New PSU

I’m being as thorough as I can possibly be. I’ve poured a lot of time and a growing pile of money into this. Would a bad piece of RAM or a bad CPU cause the kind of problem I’m experiencing?
 

ramseyrt

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Unfortunately the Biostar motherboard doesn’t have any LED indictors. It also doesn’t have an onboard pezo speaker, and I don’t have a PC speaker, so I can’t get the beep codes. I’m probably going to pick up a PC speaker today for this purpose.

I performed the following tests this morning using another 3rd party video card, as a suggestion from another forum:

Biostar MOBO #2 - Celeron 3Ghz CPU - DIMM #1 - New PSU – ATI Rage 128 PCI
Biostar MOBO #2 - Celeron 3Ghz CPU - DIMM #2- New PSU – ATI Rage 128 PCI

Biostar MOBO #2 - P4 3Ghz CPU - DIMM #1 - New PSU – ATI Rage 128 PCI
Biostar MOBO #2 - P4 3Ghz CPU - DIMM #2- New PSU – ATI Rage 128 PCI

I also tried resetting the BIOS jumper again. All tests end with the same result. Spinning fan with no display.

I am trying people suggestions to if you have one please post!

Thanks!

Rob
 
Nov 16, 2020
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On the off off chance 12 years later this notification will get to you.... did you ever find a fix? Got a similar setup from my buddy and I'm using it to strip an old hard drive but alas your post is where the google machines took me. Let's see if this time machine works,

--Rogue
 

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