Can a faulty graphics card damage a motherboard / PSU?


I've recently bought a load of components recommended by Custom PC's budget range to build my first PC.

I got everything working first time and installed Windows 7 with no problems – very happy with myself! - it seemed too good to be true. I started to try and install a PCI wireless adapter, and ever since then the problems.

The computer wouldn't recognise the adapter after countless times of installing / fitting in the right order. Then I made the mistake of leaving a DVD in the drive while tilting the PC (while off) to fit the adapter, and then standing upright again to switch on. I'm not sure if this caused a problem, but ever since then the DVD drive made a rattling/clicking noise (even without the disc in).

I can't remember exactly, but at the same point I think, on the last close down a long beep followed by too more (I think) ocurred. Since this, the PC won't even boot up to the BIOS; nothing on the screen, not even taking the screen out of standby. All the fans come on and one LED on the motherboard, but no HDD activity other than spinning.

The DVD was still making its clicking so I thought maybe this was it, I replaced it. But it hasn’t helped, still nothing.

The real problem might be that I was using an old graphics card (7800 GT) to power screen until my new one arrived (Gainward GTS 250 512MB) - just to get basic install of Windows 7 up and running.

I hadn't plugged the one 6x PCIE power lead into the card as it was just for basic 2D use and had read it wasn't necessary (a problem?). Also, I've checked the exact card online and noticed that one of the transistors or something is missing (maybe got knocked off at some point - was an old one from a friend). So, there is a good possibility the card could have been faulty! Nonetheless, it had run windows 7 no problems or glitches for a good 30 boot ups I guess.

Anyway, I received my new graphics card (Gainward GTS 250) and thought I'd finally get this PC up and running again. Plugged in the card, both the PCIE 6x pins and switched on again in hope! But nothing, no screen output or HDD reading or BIOS etc...

Now I am very worried I've fried something on the motherboard. I've tried the CMOS jumper, unplugging all non essential components, unplugging everything and plugging all core connections (tipple checking everything is well and truly connected and secure), and still nothing.

The CPU fan starts along with the GPU fan, but the strange thing is now I'm also questioning the PSU. The fan is very slow, and seems to struggle to even start sometimes, occasionally not even turning at all!

Now is this just what an OCZ Modxstream Pro 500W does, or shall I take this back and change it as faulty?

I'm starting to get very confused. Have tried the two RAM sticks, and in varying combinations in all the DIMMS also.

If you look in Custom PC I've got pretty much the exact current recommendations for their budget PC:

MSI 770 C45 motherboard
Antec Three Hundred case
AMD Phenom 2 x2 550 Black Edition
OCZ Modxstream Pro 500W PSU
Freezer Pro 7 CPU cooler (fitted with factory grease that came with it)
Gainward GTS 250 512MB
2x 2GB Corsair DDR3 10666
Samsung 320 GB
Samsung 400 GB
LG multi DVD 22x

I would very much appreciate someone’s input into this problem for me, as I’m obviously a first timer and hope I’m not overlooking some basic thing!

It’s frustrating as the PC was working fine and I was waiting for the new GPU to get really up and running. Could I have fried a component on the motherboard or damaged the PSU by using the dodgy 7800 GT card?

Many thanks for anyone’s time.

9 answers Last reply
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  1. Hi Ben

    Sounds distressing. You mention that the unit was apart and some work was being done and then it quit booting.
    The older GPU card is not likely the culprit as it seems it was working prior to the failure - plus the new one did not resolve the issue.

    Adding cards in and out can have some issues - stress on the motherboard/sockets/cables can fracture the board and solder joints, PCI/PCIe can short if the power is applied etc. It does sounds like it is low level - lack of BIOS is not a good sign.

    do you have access to a system to validate the components?

    As a course of action would remove everything not needed and start with the minimal machine.
    An approach would be to disassemble the unit - then start with each piece again to ensure it is installed correctly.

    If those elements don't work or you want to test them early use another machine or go by a facility that can test them for you.

    It may seem frustrating but suggest a slow approach - so as to not damage more materials or nerves!
    Try not to add in any other new elements in to the equation until you get a base working - it is easy to make things more complex.

    If the motherboard won't post after this you might call the tech support folks and determine warranty - next steps.

    Good luck - post your results when you get a chance!

    thx - foos
  2. Hi Foos,

    Thanks very much for the calm and well thought advice.

    Still no joy I'm afraid. I've stripped back the PC to it's core (motherboard on it's box, memory, CPU & cooler, and graphics).

    I tested components with a different PSU, and the same results. Tested with a different screen and with no results. Tested different sticks of RAM in all the slots, no results. And this is with a new graphics card.

    All conections obviously checked many times now. The conclusion I must come to is that the motherboard must have been fried / PCIE slot damaged when installing the PCI wireless card.

    Could the fact that I hadn't plugged the PCIE power lead into the graphics card mean that it was drawing too much power through the motherboard and fried the slot / chips? The PCI wireless card was also not being recognised in Windows 7 while trying to istall it - maybe too much power being drawn through the motherboard and not leaving any for the other PCI slots as not plugged directly int PSU?

    I haven't another CPU to test, could the CPU be damaged? I'm obviously looking to get my motherboard tested somehow now and possibly get a new one. Is it worth testing the CPU on another motherboard first?

    Any other comments would be greatly appreciated! I'm hoping that it was the PCIE 6x pin power lead not being plugged in that caused the problem - otherwise it was my lack of skills fitting a simple PCI wireless card after making a whole system successfully!

    Many thanks again Foos and any other comments.

  3. One of the capacitors on the card was knocked off? That could lead to problems. Ideally, if the card was defective and turned into a short, the PSU's overcurrent detection should have kicked in and saved the system. I had this happen with a defective 4850, and the computer was unharmed. However, if this happened too slowly, or just bad luck, it may very well have killed the board. If a transistor (little flat thing) was missing, then that may not have been there due to a board design change. However, if a capacitor was missing and its pins still there, it may have been ripped off (much easier to rip a cap of than a transistor).
  4. Hi EXT64,

    Many thanks for the reply.

    Definately a capacitor after your description and my memories of science at school coming back to me! So yes, one of the caps had bee knocked off - one pin stuck in solder on the card still.

    I think maybe it happened over time as I was installing W7 and then the PCI wireless card (turning on and off a fair amount), so maybe that put a particular amount of strain on the motherboard and PCIE slot or something if it was not connected to PCIE 6x pin power lead and defective?

    I've now taken the whole system apart and boxed the various parts up. I need to take the motherboard somehere to get checked over - or buy a new one if I get knowhere. Also try and test the CPU, although that was sat well in it's slot and cooler / greese applied with no problems, so I can't see this being the problem (fingers crossed!).

    Many thanks again for your reply and any other posts - I'll let you know what happens.

  5. Ouch, a missing cap. Yeah, that could cause some serious power issues on the card. And possibly what got you here was it drew too much power from the board, but not enough to trip the PSU until the board was already dead. The power regulation systems on those cards are too complex for me to more than guess on what a missing cap would do. If this was the case, hopefully only the motherboard was damaged. And yes, please keep us posted, and best of luck.
  6. Capacitors draw a lot of current during voltage spikes. One of the primary uses for capacitors is to protect other electronics from voltage spikes. Placing them in parallel to something important is a common inexpensive way of protection. If the capacitor was missing, it would have forced current into something else at startup. Startup is a time when you have a voltage spike. It will go from 0v to 5v or whatever pretty fast. Most likely a missing capacitor on a video card will do damage to the video card, but since all the components of a computer are connected electronically, who knows what the result could be?

    Your not using the 6 pin power connection may have been an issue in that maybe when in use, the circuit the capacitor was on isn't used and hence didn't cause any problems. Only when power is drawn through the slot, you have an issue. Just a theory.

    In hindsight, don't use any electronics that are missing capacitors. They are frequently important for protection.
  7. Hello everyone on this thread!

    I finally bought a new motherboard and fitted everything carefully into it and now works great! so i think we can safely say that the faulty graphics card / not plugging it into the psu was the problem and it fried my motherboard!

    I'll be recycling that gcard asap...

    Many thanks for your support.


  8. I don't know much about computers, but when my old one refused to boot up I just removed the battery on the motherboard, then put it back in and everything would work fine again... for a month or two.
  9. That would have reset the BIOS to default, which is often a good thing to try when you are having problems.
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