Member Avatar for brownnet

Hi-

I have a huge challenge that I can't figure out. I am trying to integrate the following hardware:

New Gear:
ECS GF7100PVT-M3 Motherboard
Antec EA-380 Powersupply
Intel E5200 Processor
2 MB generic RAM

Old Gear
Generic AT Case
A couple of old IDE hard drives, a few generic keyboard/mouse etc's


So I originally bought the new gear minus the Power Supply; my plan was to use an old 20 Pin-AT power supply. When I got it all hooked up and hit the power button, Only the case fan and processor fan came on. I spoke with an IT friend, who told me I needed to get a new PSU for this MB, because of the new ATX four pin plug.

So I ran down to Fry's and got the new PSU. The new PSU is 24 pin, plus it has the 4 pin ATX plug.

I got it all installed, and this time nothing fires. I notice that the new 24 pin plug has a breakaway on it that allows it to only be 20 pin. So I do the breakaway, and just plug in the 20 pin version. Still nothing. SO I try unplugging the 4 pin ATX plug, and sure enough, I'm back to square one. The case fan and processor fan come on, but nothing else.

I've tried resetting the CMOS. I do have a keyboard and mouse plugged in. I've swapped the ram with another PC. Both sets of ram work in both PC's. I've tried the monitor connected to both the VGA and the DVI connectors. I don't have any drives connected at all, in an attempt to just get to POST.

Any ideas?

Thanks in advance!

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  • Latest Post Latest Post by thepastimer

Dani AI

Generated

This thread is a good reminder that "no POST but fans spin" can come from very different things. was right to flag the PSU as an easy suspect, and correctly noted that a motherboard fault can look the same. The actual cause in this case was a simple case short under the board. Below are practical, evergreen checks and safeguards to use the next time a new build refuses to POST.

Start with a controlled minimal test. Place the board on a nonconductive surface (cardboard or an anti‑static mat), fit only the CPU and its cooler, one known-good stick of RAM in the recommended slot, and connect the 24-pin and the CPU 4-pin connectors. Attach a system speaker or watch any onboard debug LEDs. Power on and observe for beeps, LEDs, or fan behavior. If nothing obvious happens, try a known-good PSU or a PSU tester to confirm proper rails.

Look for hard shorts and physical faults before blaming components. Check for stray screws, extra standoffs, an ill-fitting I/O shield, bent socket pins, damaged or bulging capacitors, and any metal shaving or loose wire that could touch the PCB. Also verify the front-panel power switch wiring (or start the board by shorting the power pins briefly) and that all power connectors are fully latched.

Preventive habits save time: pre-fit and count standoffs against the board holes, keep extra screws in a container away from the build area, use a small speaker for POST codes, and bench-test a new board before finalizing installation. If exhaustive testing (alternate PSU, minimal components, speaker/debug card, visual inspection) still yields no POST, collect the test steps and contact the vendor for RMA or support.

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Member Avatar for thepastimer

Something might be faulty on the motherboard or psu or misaligned (such as the cpu or ram). BTW, what is the power rating of the psu?

Member Avatar for brownnet

Something might be faulty on the motherboard or psu or misaligned (such as the cpu or ram). BTW, what is the power rating of the psu?

PSU is 380 watts. Old AT one was 400.

I did remove the CPU once and made sure it was installed properly. No difference.

I have tried the two different confirmed good RAMs.

Maybe really is bad MB?

I've built three or four previous boxes and never had a problem like this!

Member Avatar for thepastimer

Do you have any other psu's you can try? 380 watts is very low; the motherboard may not be receiving adequate power after the cpu is powered.

Member Avatar for brownnet

Do you have any other psu's you can try? 380 watts is very low; the motherboard may not be receiving adequate power after the cpu is powered.

Hmm. I don't but may be able to poke around and borrow one.

The specs in the MB manual say "Minimum of 300 watts on a fully-configured system." I'd hesitate to call this fully-configured... I don't have anything except the MB connected to the PSU!

Member Avatar for brownnet

*Bump*

Any other ideas?

Member Avatar for caperjack

no need to bumb! you need to try a better psu first ,
also just for shits and whistles and not to confuse, its a ATX power supply with a P4 plug ,AT power supplies go way back to the 486 and early pentium computers.
I have seen this happen a few times now ,nothing working when p4 plug ,plugged in ,and it was the motheboard in all cases

Member Avatar for brownnet

OK, figured it out. When I took the old Mother Board off the case, I left behind a few of the screw studs attached to the case that the new MB didn't need for attachment. Those studs were probably shorting out the new MB, since it's working now. Thanks.

Member Avatar for thepastimer

Its a good thing is was something so simple.

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