Very strange hardware problem

[yanon]

I just build this a new computer system yesterday. It has Epox 9NPA+Ultra (NForce 4 ultra socket 939), 2GB OCZ value PC3200 DDR. AMD64 (Venice) 3000+, and maxtor hard drive, XFX Nvidia 6800GT 256Mbytes ( PCI express). Everything was working and done some stress testings (using PCMark2005, 3dMark2005, Sisoft Sandra Pro 2005, and Prime 95) after overclocking. That computer system was rock solid last night. My brother even played DOOMIII on it for an hour. Then the PC system has problem powering up from a cold boot this morning. It just wouldn't power up. The only way the system will power up is that I completely remove electrical charge from the system (either unplug the PS from the motherboard socket or switch the PS to off and unplug it from the wall poweroutlet) and then plug the PS back in. Then the machine will bootup but the machine will not boot into windows (it stops at the choose safe mode or continue booting into window screen). Originally, I thought the problem has to do with the PS. So, I tried Thermaltake 480 PFC, Enermax, and Antec 430 Truepower but all has the same problem. To isolate the problem, I removed all components except the CPU is left in tact on the motherboard. and the bio settings were clear through the CMOS jumper before testing. Yet, my "bare " system still can't power on without using the previously mentioned procedure.
So, the problem either has to do with the motherboard or the CPU. The Epox motherboard LED reports FF, which means initiate booting, in the diagnostic LED when the system does power up. What specific malfunctioning part could have caused such strange problem?

 

[Tbirdkid]

bios update?

 

[Bozo Galora]

You mentioned overclocking - but didnt mention what (vidcard/cpu) and how high.
The fact you can boot with an unplug, bur cant get into Windoes may mean HDD corruption (faulty PCI lock) - so a try with a dif HDD is in order.
Sometimes early mobo bios revisions do things like this with overclocked system.
I have also seen RAM overclocked too high make a non bootable system which requires:
Shutdown
Short CMOS
Unplug PSU
Wait at least a few hours - overnight even better.
Install el cheapo RAM - 1 stick of anything - PC3200 value ram etc.
Plug in PSU
unshort CMOS
Immediately boot to BIOS and set failsafe defaults, RAM by SPD


As a last shot I would reflash the bios.

 

[yanon]

Bozo Galora,

The system was rock solid running prime95. I don't think it is an overclock issue. Besides, I have tired the re-setting CMOS jumper, removing battery, and setting fail-safe but none of those option works. It is going RMA now.

 

[CrispyFried]

Well, this isnt exactly a solution but Ive found several systems that have a similar problem.. when working on it for whatever reason it wont power up after. What works is pressing the back switch while also pressing the front power button. Presto, it works

 

[yanon]

this just sounds so strange. I think there is something wrong with power circuit design of motherboard.

 

[pibb]

this may be a simple suggestion, but have you checked to make sure the power/reset switches havent came loose?