Newbie/Fried Computer?/Where to start?

By hball ยท 11 replies
Oct 8, 2005
  1. I really need help on where to start determining what I fried.

    My computer info is in my profile. I was rerouting my power cables to make my case look cleaner; there was one female molex power end (unused) that must have been touching the bottom of the bay where my harddrive is installed because when I started up the computer I heard what sounded like an arcing sound and my computer immediately shut down.

    I moved the molex cable away from any metal surface and started the computer back on by first flipping the switch on the back of the power supply. Everything powers up, the fans all run, the power supply lights up, power is going to the motherboard and my optical drive and harddrive. However, instead of powering up and then going off so I can turn the computer on with the power switch, it stays on. The activity lights on one set of ram (dual channel 1 Gig) don't light up at all; the activity lights on the other gig of ram light up only for a second and then go out completely. The computer just sits there and I don't hear the hardrive turning at all.

    I'm wondering how I could have gotten an arc from the molex when the metal ends are inset and weren't actually touching any metal surface. More to the point, I don't know where to start in figuring out what part of the computer is fried . . . the harddrive, the ram, the motherboard?

    Any help would be appreciated.

    I forgot to mention that my power button and reset buttons don't function at all anymore.
  2. Merc14

    Merc14 TS Rookie Posts: 171

    Have you reset the CMOS/BIOS yet?
  3. hball

    hball TS Rookie Topic Starter

    I have tried to get to my bios by holding down F2 when I turn the computer on, but no dice.

    My manual says something about turning off all power and removing the cmos battery for 10 minutes and then reinstalling the battery and powering up again. Is this what you mean?
  4. Merc14

    Merc14 TS Rookie Posts: 171

    Yes that is what I mean. Just make sure the PC is unplugged from the wall when you do this so all power is drained. If that doesn't work, here is a little guide I wrote to help troubleshoot.
    You are going to have to do a barebones setup and test each component. This will read a lot harder than it actually is. The initial procedure takes only around 10-15 minutes. The follow on troubleshooting may take a lot longer though. Also, please do not skip steps. Do everything in order and as listed or your troubleshooting will be flawed.

    Caution: Please remember that turning a PC off does not mean there is no power going through it. Modern systems maintain a trickle of power to keep the standby functions running. You either have to turn off the switch on the Power Supply Unit (PSU) itself or unplug the system from the wall. Unplugging is best. If you have a LED on the mobo that is lighted all the time. make sure it is out before proceeding. Also, be aware of static. Make sure you wear and ESD strap or discharge yourself on a steel part of the case before touching anything inside.

    First, unplug the PC from the wall and then open it up. Disconnect all the drives (floppy, CDROM, DVD etc.)from the motherboard (mobo) and also disconnect your Hard Drive(s) from the mobo. Do not leave the hard drives connected. The system will boot into BIOS just fine with no hard drive attached. Unplug the power from all those drives you disconnected from the mobo. Remember to disconnect the front panel firewire and/or USB ports.

    Next, remove all the RAM, except for one stick, from the mobo. Some mobos are very picky about where the RAM needs to be placed so make sure the one stick of RAM is in the correct slot as per your manual.

    Now you are stripped down to a barebones system. The PSU, the mobo itself, 1 stick of RAM, the CPU/HSF and video card. Reset your CMOS/BIOS while the system is stripped down, unplugged and open. You do this by removing the battery and then moving a jumper near the battery around. Usually there are a set of three pins with two covered by a jumper. You move the jumper from pins 1&2 to pins 2&3 and let it set for a few minutes then reset the jumper to pins 1&2 and replace the battery. CMOS and BIOS will be back at default settings after doing this.

    Now check that everything is seated correctly, both the 4 pin and 20 or 24 pin power is connected and secure and if so then plug the PC back into the wall and make sure that any LEDs that should be lighted on the mobo are lighted. If all is still well then turn it on. Hopefully she boots right back into BIOS.

    If you get back into BIOS you can start troubleshooting by turning the PC off and unplugging it and reconnecting peripherals one at a time. The idea here is to connect and reboot until something hangs your system up This presumably is the bad piece of gear.

    If you cant get into BIOS and have the same problem as before then you know it is either the PSU, the RAM, the CPU, the mobo itself or the video card. Change out each these until you get into BIOS. I would start at the PSU as it is usually the guilty party in a situation like this and is also easy to change in and out you are down to just 2 plugs now remember). Next up would be the video card and/or RAM and if still no luck then things get hard as you now have to consider either the CPU or the mobo.
  5. hball

    hball TS Rookie Topic Starter

    Did what you said, disconnected everything, changed the jumpers, took out cmos battery and let everything set for 10 minutes.

    Plugged the power back into the motherboard, replaced the battery, moved the jumpers back.

    When I reconnected the power supply and turn the power supply switch back to "on", the whole computer powered up and stayed powered up. I know that it's just supposed to start the cpu fan for a moment and then go off. Then I'm supposed to use the computer "on" switch to boot up. This won't let me do that, the power switch is totally useless and the computer fans, motherboard, video card, etc. all have power to them. The motherboard light is on and the fans are all running.

    I was hoping that this would be a clue as to what is wrong. This leads me to believe that it's the motherboard or processor.
  6. Merc14

    Merc14 TS Rookie Posts: 171

    It sounds like the PSU was shorted out as you suspected. Did you unplug the PSU/PC fom the wall? SOmetimes that will rest it. If you did then you may need to replace the PSU. Do you ahve another you can test the system with?
  7. hball

    hball TS Rookie Topic Starter

    Before I go further, I want to thank you for your help.

    I unplugged the power supply at the back of the computer. I just put in a brand new power supply (same brand), an Ultra X-Connect 500 watt supply and have the same problem. It can't be my power supply.
  8. Merc14

    Merc14 TS Rookie Posts: 171

    No problem, wish I could be of more help but, unfortunately, it sounds like your mobo got zapped. HJopefully the CPU and RAM etc. are ok. Your PSU would have, or should have, stopped a short from reaching the mobo so the arc must have travelled up a standoff and into the board. You'll have to remove the mobo and visually inspect it. Then you can try to boot outside the case using the guideline as before. You'll have to check each item to make sure it wasn't shorted out. Sucks but what can you do. Let us know how it goes. That molex should not have shorted like that so I'd trash that lead.
  9. hball

    hball TS Rookie Topic Starter

    Thanks again, for your help, and I will update you on my progress. First off, I ordered a new mobo (same as before). Hopefully, the problem will be fixed with that; if not, the processor will be next since it's cheaper than 2 gigs of corsair ram.
  10. hball

    hball TS Rookie Topic Starter

    Great news, got my mobo today, installed it and the computer booted up like it should. Everything seems to be ok.
  11. Merc14

    Merc14 TS Rookie Posts: 171

    That's great! Glad it worked out and nothing else got fried. I's inspect everything very carefully to make sure there isn't a short somewhere that will effect you again.
  12. hball

    hball TS Rookie Topic Starter

    Doing a check of all my molex connectors; used shrink tubing to cover the ends of unused molex connectors.

    Also ran memtest86 to ensure my ram wasn't damaged . . . everything fine there.

    Thanks again.
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