Results 1 to 14 of 14
  1. #1
    Star Lounger
    Join Date
    Dec 2009
    Location
    Colorado
    Posts
    75
    Thanks
    3
    Thanked 0 Times in 0 Posts

    Help diagnosing dead PC?

    My son and his friend upgraded the cooler on the friend's PC to some uber-mondo Cooler Master. They put everything back together, and... nothing. Monitor doesn't turn on. Worse, no BIOS beeps. The friend says the BIOS did definitely beep before.

    Mobo has power. Fans & graphics card have power. Everything looks fine, except it's dead.

    Given no BIOS beeps, I suspect either a dead mobo or, more likely, they didn't get good thermal contact to the CPU and the CPU (Intel) fried.

    Bow can we tell if the CPU is dead but the mobo healthy? How can we tell if the mobo is dead but the CPU possibly healthy? Or are there any other likely causes (e.g. loose power cable), and if so, how would we detect them?

    Thanks!

  2. Subscribe to our Windows Secrets Newsletter - It's Free!

    Get our unique weekly Newsletter with tips and techniques, how to's and critical updates on Windows 7, Windows 8, Windows XP, Firefox, Internet Explorer, Google, etc. Join our 480,000 subscribers!

    Excel 2013: The Missing Manual

    + Get this BONUS — free!

    Get the most of Excel! Learn about new features, basics of creating a new spreadsheet and using the infamous Ribbon in the first chapter of Excel 2013: The Missing Manual - Subscribe and download Chapter 1 for free!

  3. #2
    Super Moderator jwitalka's Avatar
    Join Date
    Dec 2009
    Location
    Minnesota
    Posts
    4,662
    Thanks
    67
    Thanked 531 Times in 480 Posts
    Are you sure they plugged all the power supply cables in including the 4 or 8 pin connector?

    Jerry

  4. #3
    Plutonium Lounger Medico's Avatar
    Join Date
    Dec 2009
    Location
    USA
    Posts
    12,625
    Thanks
    161
    Thanked 929 Times in 851 Posts
    I wonder if the new cooling requires more power. Many PC's, especially OEM PC's are underpowered.
    BACKUP...BACKUP...BACKUP
    Have a Great Day! Ted


    Sony Vaio Laptop, 2.53 GHz Duo Core Intel CPU, 8 GB RAM, 320 GB HD
    Win 8 Pro (64 Bit), IE 10 (64 Bit)


    Complete PC Specs: By Speccy

  5. #4
    4 Star Lounger
    Join Date
    Mar 2011
    Posts
    546
    Thanks
    3
    Thanked 33 Times in 28 Posts
    The monitor doesn't come on and you can't hear any beeps, but do any other peripherals work? Mouse (light, if it has that type of detection), or keyboard light? Lights on loudspeakers, if they have them? (Yes, I know that has nothing to do with the computer, but if they are plugged in and lit then you know you might expect sound under the right conditions.) For that matter, is there a light on the Monitor to show that it is powered on, and is it securely connected. Better still, do these peripherals work with another computer?

    If the monitor did come on, you might get the preliminary screen showing function keys for BIOS, Boot Selection, Safe Mode, and System Restore and if you might, for example, try booting from a bootable CD or flash drive, which would bypass the normal boot drive. If it worked, you would know that you have boot drive trouble, which admittedly is only one of a large number of possible causes, but you have to start eliminating suspects (say, is this a Cold Case?).

  6. #5
    Super Moderator CLiNT's Avatar
    Join Date
    Dec 2009
    Location
    California & Arizona
    Posts
    5,404
    Thanks
    128
    Thanked 488 Times in 449 Posts
    Strip it back down and redo everything that you've already done.

    It's very dificult to "fry" a modern CPU. If good contact isn't made, it just won't work at all, or it's
    fan will huff and puff and will refuse to start.
    If anything it's probably motherbored related. Ensure that you have no short circuits on the board and that the
    boards capacitors are drained prior to rebuilding from a near on state.
    Take electrostatic precautions seriously when working on a motherboard.
    Also ensure the BIOS pin on the board hadn't inadvertently come off or is in the wrong possition, if applicable.
    As stated above, also ensure all needed power cables are in place prior to testing.

    It's also possible that the cooler's position on the processor is finicky. I've run into a situation before where I had to reorientate
    a heatsink on the processor in order to get it to actually work.
    Last edited by CLiNT; 2012-09-07 at 08:56.

  7. #6
    Lounge VIP
    Join Date
    Apr 2011
    Location
    Scotland
    Posts
    1,168
    Thanks
    44
    Thanked 134 Times in 115 Posts
    An incorrectly seated CPU will almost always result in failure to POST, and fitting a new heatsink is an ideal opportunity to accidentally disturb the CPU.

    Even if they didn't remove the CPU during the fitting of the new heatsink, they may have disturbed the retaining clip or accidentally twisted or moved the CPU in it's socket with the mass of the new heavyweight cooler.
    In God we trust; all others must bring data.

    - William Edwards Deming. 1900 - 1993

  8. #7
    Star Lounger
    Join Date
    Dec 2009
    Location
    Colorado
    Posts
    75
    Thanks
    3
    Thanked 0 Times in 0 Posts
    Thanks for all the suggestions!

    As far as I can tell, all power cables are properly plugged in. I'm pretty sure it's not underpowered. The PC has 3 250GB WD hard drives, a big graphics card (EVGA GTX 560ti), and 4GB of RAM -- but it has a 1000W Antec TruePower Quattro 1000 power supply.

    But, hmmm... No, the mouse does **NOT** light up!! It flashes briefly when I plug it in, then it goes out. I've never seen that before. What does that indicate??

    Unless the "no mouse light" tips you off to the problem, I guess stripping it down and trying again is the best answer. CLiNT, I'm very surprised to hear you say it's hard to fry the CPU. I actually DID fry a CPU when putting on a new cooler once, but that was 5-8 yrs ago so maybe things have changed.

  9. #8
    Super Moderator CLiNT's Avatar
    Join Date
    Dec 2009
    Location
    California & Arizona
    Posts
    5,404
    Thanks
    128
    Thanked 488 Times in 449 Posts
    I guess it would depend upon what your definition of fried is.
    static electricity can definitely damage a CPU, as well as RAM and other sensitive components.

  10. #9
    Plutonium Lounger Medico's Avatar
    Join Date
    Dec 2009
    Location
    USA
    Posts
    12,625
    Thanks
    161
    Thanked 929 Times in 851 Posts
    If anti static precautions were not used, most electronics can be damaged. I worked in the Aerospace field as an electronics specialist, troubleshooter. When ever we worked on the IC boards we had to wear anti-static straps constantly, and this was with devices that had an extremely high cost with very stringent inspection and manufacturing requirements. We're talking mil-spec devices here and we had to constantly guard against static discharge.

    Now compare these safeguards on equipment worth hundreds of thousands to millions of dollars to our PC's that might cost a couple of grand for high end devices. What kind of quality control went into these devices from the start. Then add additions and/or upgrades done by less than qualified individuals and you can see the potential for damage.
    BACKUP...BACKUP...BACKUP
    Have a Great Day! Ted


    Sony Vaio Laptop, 2.53 GHz Duo Core Intel CPU, 8 GB RAM, 320 GB HD
    Win 8 Pro (64 Bit), IE 10 (64 Bit)


    Complete PC Specs: By Speccy

  11. #10
    Star Lounger
    Join Date
    Dec 2009
    Location
    Colorado
    Posts
    75
    Thanks
    3
    Thanked 0 Times in 0 Posts
    I meant "fried by heat." It sounded like you were saying a badly-seated cooler would shut things down but not cook the CPU.

    I've worked on a fair number of PCs and I'm never more than modestly careful with static. I mean, I don't set them down on carpet, and I try to remember to touch the case ground before I pull it out, but that's about it. But my son is a fanatic about static (ooh! a static fanatic! ) so I'm sure they were careful.

  12. #11
    Super Moderator CLiNT's Avatar
    Join Date
    Dec 2009
    Location
    California & Arizona
    Posts
    5,404
    Thanks
    128
    Thanked 488 Times in 449 Posts
    With many CPU's, if the heatsink were not seated correctly, it will just not function at all until the seating or contact was corrected.
    And that would mean "dead everything" except for the case fans.
    One would have to be extremly persistant and careless with a CPU in order to damage it in this way.
    It would also depend too on the quality of board as well.

    I'm not necessarily saying that you/he actually did this.
    Last edited by CLiNT; 2012-09-07 at 08:52.

  13. #12
    Star Lounger
    Join Date
    Dec 2009
    Location
    Colorado
    Posts
    75
    Thanks
    3
    Thanked 0 Times in 0 Posts
    Well, we finally got an opportunity to tear it apart... and out of the case, it worked fine! We didn't remove the cooler, and fortunately we didn't have to. We reassembled everything back in the case, and it's still happy. Hard telling what went wrong when they installed it the last time, but it's working now.

  14. #13
    Plutonium Lounger Medico's Avatar
    Join Date
    Dec 2009
    Location
    USA
    Posts
    12,625
    Thanks
    161
    Thanked 929 Times in 851 Posts
    Could have been a connector or similar. Glad you got it working.
    BACKUP...BACKUP...BACKUP
    Have a Great Day! Ted


    Sony Vaio Laptop, 2.53 GHz Duo Core Intel CPU, 8 GB RAM, 320 GB HD
    Win 8 Pro (64 Bit), IE 10 (64 Bit)


    Complete PC Specs: By Speccy

  15. #14
    Super Moderator CLiNT's Avatar
    Join Date
    Dec 2009
    Location
    California & Arizona
    Posts
    5,404
    Thanks
    128
    Thanked 488 Times in 449 Posts
    Maybe a standoff was slightly out of place or tipped over on the original install, or some other form of "short" that has taken place somewhere on the motherboard.
    These thing can be easy to overlook when doing a build.
    DRIVE IMAGING
    Invest a little time and energy in a well thought out BACKUP regimen and you will have minimal down time, and headache.

    Windows 8.1, 64 bit
    Motherboard: DX58SO2*Chipset: X58 Express/Intel ICH10*BIOS: SOX5820J.86A.0888.2012.0129.2203*Processor: Intel Core i7 CPU X 990
    GPU: Nvidia GTX 580*Memory: Corsair 12 GB, 4x3@1600*PSU: Corsair HX1000*Hard drives: REVO X2 160GB*OCZ VERT X3 120GB*5 mechanical storage drives (12 TB) total.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •