New C2D Rig keeps burning inside...

[Zinthar]

I previously posted this on the General forum in err...it's far more appropriate here.

I built my first rig back in August with an E6400 and 965p-DS3 mobo -- everything worked perfectly and I got a fully stable overclock to 3.4 Ghz.

I decided to build a near identical system for my brother, using the following hardware:

CPU: C2D E6400
Heatsink: Tuniq Tower 120 (w/ AS5 thermal paste)
Mobo: Gigabyte 965G-DS3 (variant of the 965P-DS3 w/ integrated video solution included)
RAM: Geil 2x1GB DDR2-1000 5-5-5-15 1.9V-2.3V
Video Card: X1950XT 256MB
PSU: Seasonic S12 650W
HDD: Seagate Barracuda 320GB
Optical: Asus SATA 16x DVDRW Drive
Case: Centurion 532

I assembled the rig with no apparent problems. I connected everything except for a few of the case connections to the mobo. The system posted immediately and I flashed with a floppy using Gigabyte's Q-Flash to the latest 965G-DS3 firmware. The only problem that I encountered was that the Tuniq Tower's fan would not start immediately using the Auto fan settings on the motherboard. Switching to the Intel QST setting corrected this.

I installed Windows XP Pro to the hard drive and installed the chipset drivers from the Gigabyte CD.

I turned off the computer for a moment to connect the case's front USB port to the motherboard. Upon turning it back on, the system died immediately (before posting) and smoke came out of the PSU (I was using an Enhance 5150 500W PSU initially). Great...bad PSU. I RMAed the PSU and switched to a Seasonic S12 650W.

Hooked everything up again and started the system... it posted but I was never able to see anything but a black screen once Windows started up. I shut the system off and upon restarting the video card wouldn't send a signal to my LCD...and the Radeon's fan would continue spinning at max speed as if it wasn't receiving a signal from the motherboard (the one in my system spins up and then drops upon system posting). I removed the video card and plugged the VGA cable into the motherboard's onboard video. No signal. At this point I smelled something burning inside the case. I shut off the system immediately.

I can't tell what all is damaged. I turned the system on again to try to assess what I needed to replace and there was more burning -- it came from around where the PSU is mounted at the top of the case...or perhaps from the motherboard around where the CPU is...hard to tell. When I turn the system on now it just continually reboots itself. It does seem to be receiving power though...at least the power button is functioning and the case fans and optical drive were receiving power. I'm hoping that this means that the Seasonic is fine and the motherboard is what was burning (hopefully without damaging the CPU or RAM).

I also have considered that this is a 965 board and it may not have been happy with my GEIL 1.9-2.3V RAM (I never changed how much voltage the mobo was feeding the RAM in the BIOS). Is this a possible cause to a PSU dying and then burning occuring somewhere in the case with the new PSU.

Any thoughts on what went wrong and what needs to be replaced. I'm thinking of initially just pulling out the motherboard and RMAing it and replacing it with an ASUS P5b deluxe (I have a DS3 in my build and I'd like to give the P5B a try). Is it likely that the PSU, E6400, or RAM is also damaged (and is there an easy way to tell without risking putting them in my rig)?

And more importantly...is it possible that the RAM could cause the motherboard to fry (and is it possible for a motherboard to fry a PSU)? I know 965 series mobos are picky about DDR2 spec RAM, and this Geil is 1.9-2.3V.

Recommendations from more experienced builders on what I should do?

 

[daveybrat]

Unplug the power supply and examine the 24-pin connector inside and on the motherboard. Check to see if there is any brown or black burnt marks inside.

It sounds like either the motherboard or power supply is bad, which should not affect the rest of the system. Unplug the front usb ports as well as they may have had a short in them that caused all this in the first place.

 

[sieistganzfett]

wow. i would just rma everything. but it sounds like, if the front usb that you connected (when pc was off) was plugged in correctly, (meaning ground +5 -5, etc. if different connectors for each was plugged into the corresponding pins on the mobo correctly) was what shorted out the mobo and killed the power supply at the time. replacing the powersupply gives power, but it seems the mobo is the smell from what you said. i would take everything out of the case and disconnect that usb front panel that may have shorted it out.

 

[mechBgon]

Some motherboards have four bolt holes up the rear edge, and some have only three. This one's got only three. So make sure you don't have an extra standoff underneath the board in the location circled here :camera:. It would be hitting the back of the board and possibly shorting stuff out.

 

[Zinthar]

Thank you all for your responses. I hadn't considered the possibility that the front USB ports had shorted out the mobo & power supply. It possibly could have been the internal case speaker as well I suppose. In that case, I can't take a chance on using this case and should RMA it as well. I think I'll RMA the motherboard and case and reassemble my components and hope the Seasonic power supply works since it seemed to still be powering the system before I disconnected everything (so long as its motherboard pins seem to be undamaged).

I'll double check the rear standoff as well, but I'm fairly certain that I placed those all correctly.