Unusual boot problem with self-built computer

[N-TWO-O]

Hey, I'm new here (fairly sure you can tell by the number of forum posts) but I've been having a problem with my computer for the last several months or thereabouts but been dealing with it with a workaround.

Here are my system specs to get started with:

Windows Vista Home Premium 64-bit
ASUS P5N32-E SLi motherboard
Intel Core2Duo E6600 2.4GHz (overclocked to ~3.4GHz) CPU
NVidia XFX GeForce 8800GTX GPU
Corsair XMS2 Dominator 4.0GB (4x1.0GB) RAM
X-Clio 850W PSU

Several months ago my computer (self-built which I had for another several months beforehand) decided to stop booting. Everything would power up but the display wouldn't power up and the machine wouldn't boot to the post screen. I would get an intermittent clicking sound, as if something was trying to catch in order to boot (possible mainboard short?). At first I suspected it was my graphics card so I took out my 8800GTX from the PCI-E x16 slot and replaced it with my old 7950GX2, and when I powered up the machine it would boot up fine... on replacing the 8800GTX back into that same slot, it wouldn't boot up again.

I sent the graphics card on RMA back to scan.co.uk and they said that the card had no faults which just made me more confused as I now had no idea what the problem was. I eventually found a workaround by placing the 8800GTX in the lesser PCI-E x8 slot, and where it DID work, I felt as if I was losing the major potential of my card.

Last night I opened up my computer once again to try the PCI-E x16 slot again to see if it worked again, but once again the system failed to boot, however I then stumbled on the solution by mistake. Being lazy I thought I'd just leave my computer laying on its side to minimise movement (ATX Tower case), and it was here that I realised that the system only boots up in this horizontal position when the 8800GTX is in the PCI-E x16 slot. I can continue to use the computer in the vertical position but it refuses to (or has a very small chance to) boot in the vertical position.

All my drivers are uptodate and Vista is uptodate (although software shouldn't have any effect on this situation). I've tried pulling out and putting back in the hardware components to no avail, I've even tried nudging things up a bit while in a vertical position during boot to give the system the thought that it was "horizontal", again to no avail.


Does anyone know what would cause this problem? If it was a short, why would it then work flawlessly in a horizontal problem? As far as I was aware, the mainboard circuitry wouldn't be affected by angular positioning, but maybe I'm wrong. I tried a bios update once and I think I was having problems with it so went back to stock bios drivers.

Cheers

 

[Lexluethar]

Keep your computer in the horizontal position - problem solved

Otherwise I would look into the issue being connectivity between the card and the main board. First try cleaning off the connectors of the video card. Second i would replace the card.

 

[Nagasama]

do you use the screws to secure the card to the case?
sounds like the pins of the card are not making good contact with the pcie slot when the comp is upright. the 8800gtx is a heavy card and those screws need to be used.
its NOT the card. if it was, it wouldnt work no matter the position of the case.
if anything its the pcie slot of yor mobo. secure it if it is not and see what happens. and if you are usinig a "screwless" case, use the screws anyway.

 

[N-TWO-O]

Yeah I always use the screws to secure the card. This morning I did power up the system but it failed to boot up, even in the horizontal position. I spent the whole day cleaning it, removing all the dust that had collected up in the case and just pulled out and replaced everything to get good contacts. After this it still didn't work, and I used a trick I read up about of using a rubber on the connectors of the graphics card to clean it. My computer now boots up, but again its only in the horizontal position.

I'm not too sure what I can do to emulate a horizontal "sense" to the system while in a vertical position however, and it really is a big computer to be kept in a horizontal position on the floor... this will also mean its more likely to gather dust as all the fans are no more than 10 cm from the ground.

I know its definitely not the card, questioning whether maybe theres a short in my motherboard however. When I power up and the system fails to boot, my DVD-RW drive does make intermittent clicking, I'm not sure why but maybe that will help someone to help me identify the problem.

I have two PCI-E x16 slots and this boot up problem occurs with BOTH of them, so I don't think the card weight is the cause of the problem. I was thinking its possibly an IRQ conflict with something else, but being a novice with IRQs and the rest, I can't really start to think why that would be the case or how I would go about resloving it.


Could there be an error with my motherboard concerning the x16 bus? Would a BIOS update have any effect on this particular problem? I tried my 7950GX2 in the x16 slot and it worked again without error.

This problem really is leaving me with no ideas. The 8800GTX connectors are fine as they do definitely work, there isn't a problem with the x16 slot as the 7950GX2 works flawlessly in both x16 slots... all ideas or suggestions welcome.

 

[Nagasama]

hmmm. what happens if you try to turn it upright after it has booted horizontally? does it shut off? if it stays on, can you restart?
wierd noise from dvd? try unplugging your dvd drive and see what happens.

 

[N-TWO-O]

It stays on when upright after standing it up into an upright position, and although the DVD-ROM does click when the system is failing to boot, it has no significance on whether the system boots or not, whether plugged in or not. And when I do restart in the vertical position, it may or may not boot which would give the assumption that the connectors have come loose, but if that was the case, wouldn't the display shut off altogether while running?!

Having said that I didn't think it was the connectors on the graphics card, I think it actually might be some sort of problem between the graphics card and the x16 slot. Last night it failed to boot again, in both the vertical and horizontal position. When I tried moving the card around while in the horizontal position, the display fired up and the system booted and continued to use in the vertical position. After restarting, the system again failed to boot, but when I tried forcing the card up, it fired back to life. The conclusion therefore is that it is a connector problem but that still doesn't explain why this happens with BOTH x16 slots and not the x8 slot.

I just turned my computer on now and managed to boot flawlessly, so chances are that its "lodged" in a way that it can't possibly move regardless of the GTX's weight, but I very much doubt I've seen the last of this problem. Thanks for all your help... if anyone has any explanation as to why this happens with the two x16 slots and not the x8 slot, do give ideas but it does seem (for now) that the primary problem has been solved.

 

[Nagasama]

man i am totally stumped. like you said, it sounds like asome sort of connector problem...
the mysterious world of computers lol...

 

[N-TWO-O]

Indeed, but I can now confirm its a connector problem.

Must be some sort of way the x16 slot was manufactured compared to the x8 slot. Its to do with the weight of the unsupported side of my graphics card. When I push it up, I can hear a clicking noise (basically clicking into place) and when I release it, it clicks again so it must be falling out of the slot... to an extent... I say to an extent because the computer doesn't shut down when released, but when I power up the system and it doesn't boot, if I push it up clicking into place it comes to life.

As I said, it must be some way that the two different PCI-E bus slots were made because I only have the problem with the two PCI-E x16 slots yet the x8 doesn't have the same problem. I'm going to try the primary x16 slot again and see if theres any better support in that one, but I'm really not keen on having to push the card up everytime I want to turn on the computer. I'd need some sort of way to keep it in place, and keeping the computer horizontal isn't an option. Any ideas?

 

[Nagasama]

lol...maybe like wedge a stick under it or something? seriously.
thats why i asked if you had it securely screwed in...thats a heavy card to be riging on the mobo....and it sounded to me as if the weight had been pulling it down out of the slot. i guess its heavy even with the screws in place. but its odd that the back side would come loose enough to foul up the connection with those screws in.
prop it up, or new mobo i suppose.

 

[N-TWO-O]

Yeah I'll need something to prop it up, just don't know what.

The card is screwed in and secure, however the unsecure end of the card seems to be getting weighed down, and so it is probably bending the card in such a way that the connectors further from the back of the case are dropping downwards. It doesn't even need to be pushed up that far, but there is a massive gap between the bottom of the case and the graphics card (which is in the lowest position possible on the motherboard) of about 4-6 inches due to the power supply unit being housed at the bottom of the case (Antec 900 gaming case). I'm not sure what I could get to push it up which would be stable enough to support the end of the card, but there is also an intake fan about 5 or 6 inches infront of the graphics card and PSU and I can't afford to have the air regulation be interferred with in any way.

I may upload a pic of my machine in my next post to explain what I mean.