Fans spin, no post, no led, no HDD - MoBo or PSU dead?

[krakenslayer]

I thought it would be wise to ask for some advice before I go out and start blindly buying new pieces of hardware to see what fixes my problem.

This morning my girlfriend's computer died on me. I lifted up the cube-style case at an angle so I could get a closer look at the USB ports in the front (one appeared to be broken) and the screen went blank and the dreaded smell of burning electronics reached my nostrils. When I tried to reboot, nothing happened: (apparently) no power, no LEDs, no spinning HDD, nothing.

At this point, I thought I'd somehow blown the PSU. Crossing my fingers, toes and several other parts of my anatomy that I won't describe, and praying to God, Jesus, Mary, Allah, Thor, Ganesh and Satan all at once, I turned off the PSU switch at the back, removed the power cable and then reconnected everything...

Now all the fans power up and spin when the PSU is turned on via the I/O switch on the back of the case (which, as far as I'm aware, did not happen previously unless I actually booted the machine from the power/standby button on the front), and the core temp is shown on the digital display (without any backlighting). Still no LEDs, no disk spinning, no beeps, no post, nothing - dead. Pressing the "on" button on the front does nothing at all.

It's looking more and more like it's the motherboard that has been fried. I noticed soon afterwards that the video card seemed slightly dislodged, like possibly lifting the case at an awkward angle to the ground has yanked the video cable and pulled the card from its slot. Reattaching it made no difference whatsoever.

My questions are:

Is it possible that the graphics card being removed while the machine was on could have destroyed the motherboard?

Does this sound like a fried motherboard to you?

The fact that I can't actually see any melted circuits or wires on the board makes me consider the possibility that it's a PSU issue, while the spinning fans makes me think it's a blown mobo. I don't know which to replace, and I don't want to start replacing parts in a scattershot fashion without first seeking advice.

My biggest problem, I guess, is that I don't own any other desktop PCs with which I could swap parts to try and determine the culprit, so I'd be happy to simply accept any educated guesses you guys could provide.

My girlfriend's rig is as follows:

Motherboard: ASRock AliveNF4G-DVI
CPU: AMD Athlon 64x2 5000+
GFX: ASUS EAH3850 Magic 512MB
RAM: 3GB DDR2-800 (2x512MB, 1x2GB)
HDD: Maxtor 80GB (I know)
PSU: Advance MPT-460XP (460 watt)

I'd really, really appreciate any feedback, because my GF is doing everything she can to make me feel guilty about this (you know - since it died while I was using it, there's always that sour implication that it was somehow my fault).

 

[krakenslayer]

Nothing at all? Honestly, I won't hold you responsible for wasting my money if you're wrong - I just want some educated guesses on whether it's the MoBo or the PSU that's gone.

 

[LeadWake]

Well Kraken, looks like you and I are in the same Boat sort-of-speak. However, I didn't get that electronic fry-ing smell emitting from my computer though so I'm not sure what is the culprit. Seeing though that your comp did start wafting an unpleasent aroma, it seems likely that the motherboard could possibly be fried. On the other hand, bad memory (not alzheimers) is a lot of times a factor in preventing a computer from booting up. Since you have multiple sticks I would initially try removing some and just leaving 1 in to see what happens. Check all the power cables from the PSU to make sure there is no fraying or exposed wiring.

I'm not sure I helped any, but I would say more often then not, the motherboard or memory is usually the leading cause of a comp not booting up.

 

[krakenslayer]

Well Kraken, looks like you and I are in the same Boat sort-of-speak. However, I didn't get that electronic fry-ing smell emitting from my computer though so I'm not sure what is the culprit. Seeing though that your comp did start wafting an unpleasent aroma, it seems likely that the motherboard could possibly be fried. On the other hand, bad memory (not alzheimers) is a lot of times a factor in preventing a computer from booting up. Since you have multiple sticks I would initially try removing some and just leaving 1 in to see what happens. Check all the power cables from the PSU to make sure there is no fraying or exposed wiring.

I'm not sure I helped any, but I would say more often then not, the motherboard or memory is usually the leading cause of a comp not booting up.

The good news is, I fixed it. The issue seems to have been with the broken USB ports on the front of the case; the motherboard must have been shorting off into them. To LeadWake - if your symptoms are the same as mine, I highly recommend you try removing all disc drives and non-essential headers (as well as all but one of your RAM sticks as you suggested) from your system to make sure a fault in one of your other components isn't sucking all the power out of your motherboard.

The bad news is, I only discovered this after spending £40 of my girlfriend's money and £30 of my own on a brand new motherboard and PSU. Quite a lot for someone who's just been made redundant and is trying to live on £40 a week . Now I'm telling myself (and my GF) that I think I tried removing all the USB headers from the old board at some point in my hours of desperate diagnostics, which would mean the short had fried something in the old board and the replacement wasn't a waste of money - but I can't be sure and I'm afraid to test the original MoBo again in case it does turn out the whole enterprise was a total waste of cash. As for the new PSU, I might try returning it to the store and see if they'll give me a refund, or maybe I'll sell it on eBay.

On the upside, the new board does mean I can upgrade to a Phenom x4 when I get a new job.