Computer smell on attempted start-up

Hi there...

Here's what happened:
- Turned on pc in usual way
- cd drive light remains on, screen light flashing, pc green and red light remain on...and a smell...and a blank screen
- realised a book may have been covering the top vent - cooling the whole pc...checked the fans and cleared some 'fluff'
- Checked all cables and cards etc are in securely.
- Fans seem to be going round...heard the usual fan noise (however can check this with side panel off...if necessary)

Previous message of 'over-voltage' (on start up) stopped about 3 months ago...pc seemed to be working fine. My computer knowledge is beginner with some experience of hardware building.

Can someone shed some light on this? Please only reply if you are familiar with this issue.

Many thanks for your time.

10 answers Last reply
More about computer smell attempted start
  1. common problem with generic power supplies. follow your nose. if you smell something its the power supply blowing a capacitor or something along those lines. if this is the case, just go grab a new one and all should be well.

    Worst case is that your motherboard will actually have burn marks on it from burning its circuits, but far less likely.
  2. "over-voltage' (on start up)"
    Sounds remarkably familiar to a problem I was having with my Asus P5RD1-V about 6 months ago, apparently my motherboard had decided to die on me and my family got a new one ( I am away for studies atm, so I have no idea what happened and some dodgy guy did the repair for my family).
    So yeah unless your PSU has died you are looking at a new motherboard.
  3. I agree that a capacitor likely has gone.

    It could be the PSU, Mobo or Video Card.
    You might try using your nose to see if you can trace its source.

    Most devices have some rundancy in the Caps, so if one is gone it may still work, just don't expect it to last long.
  4. Sounds like a mobo capacitor to me. If you find any that are bulging or leaking, that's it. Google is your friend, if you want to find pictures of what a bad cap looks like.
  5. hi guys...

    the smell went on the second start-up attempt (I had cleared some gunk from the top vent/fan area). The motherboard looks clean, healthy and normal in colouring etc...

    Thanks very much for your replies...tis lovely to have some support and knowledge.

    Some questions in response:

    Further info on terminology is required: Do all the PSU, Mobo and Video Cards have capacitors? (as the smell has now gone I'm unsure which one)

    What is a Mobo? say 'most devices have some redunancy in the Caps, so if one is gone it may still work'...please can you expand/explain this for me?

    Are the PSU or Mobo easy to replace (I'm fine with video cards etc)? and do I need to check compatability?

    Thanks again...your support is highly valued.

    PS: just to ease my mind...does it sound like the hard drive is fine then?
  6. Yes, all of those assemblies contain capacitors. Their primary functions include acting as filters.
    Mobo = MOtherBOard.
    Redundancy in the capacitors means there may be more than one doing the same job, so if one fails the circuit may still function, though possibly not as reliably.
    Replacing a PSU is pretty easy. Most people have a lot more trouble recognizing the need to choose a quality one. Antec, Corsair, Seasonic, OCZ, and PC Power and Cooling are all good ones.
    Replacing a motherboard is more of a big deal, as essentially you'll be rebuilding your PC. There are plenty of [illustrated] online guides for doing it; Google is your friend. The most common mistakes that noobs make are not using the proper standoffs (using none, or putting in extra ones, which can short out a mobo), or forgetting to plug in the 4- or 8-pin CPU power connector (fans [and lights] will come on, but nothing else).
  7. What brand and model is your current PSU? If a capacitor (or other component) inside it is the source of the smell, turning it on could pass harmful voltages and/or electrical noise to your PC. A cheap PSU tester ($16-$20) can tell you if the right voltages are present, but nothing about electrical noise. has a review in which an oscilloscope trace of one rail of a PSU with a blow cap showed a virtual chain-saw racket of electrical noise passing through.
  8. Using one of those PSU testers (mines from thermaltake, but most are the same) you will see one of the voltage lines take a few seconds longer to reach the desired voltage, or it will show nothing at all and just beep at you. Cheapest way to determine the problem is open up someone else's system and borrow their power supply
  9. Hey guys...

    right, I've had a good read of your advice and comments...a big thank you for these.

    I've had a good look at the pc. the caps on the mobo (I'm getting the lingo now lol) are looking really clean and good/healthy. The caps on the graphics card look fine too...I've cleaned off the fluff/gunk from the PSU and checked other fans.

    processor: Intel P4 3Ghz 800FSB
    hard drive: 120gb Maxtor 8mb Cache (SATA)
    mobo: ASUS P4P800S
    PSU: Codegen 400w Model 300xx (I'm in the UK btw)

    I've found that the smell only occurred the first time I turned it on and so am unable to find the source.

    I've found our pc records from when we got it built...there was a problem after two years and they did a test - and found it was the graphics card that caused the prob. (The previous graphics card was: Nvidia FX5200 128DDR.) The CURRENT graphics card is: Club3D 128MB GeForce FX5200. (to me this sounds very similar to the previous one?!)

    So...I'm now wondering - Do you think the PSU has been causing the problems with the previous messages of "CPU Over Voltage Error" (of which disappeared a couple of months ago) and the previous replacement of graphic card?

    Wonderful to know you are out there...feel the karma please...i wholeheartedly appreciate your assistance and interest.

  10. Can you still help? Has all gone quiet here. Please keep me posted on what you are thinking. Thanks
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