Investigating dead PC

Greetings everyone.
My computer has stopped turning on after a storm. No lights, beeps, nothing.
Configs are as follows: i5 2500k, GTX 760, Gigabyte GA-Z68X-UD3-B3 motherboard, 2 sticks of 1333MHz 4GB RAM and a Corsair TX650M PSU.
I have tested the PSU by the method of shorting out the green and black wire connectors with a paper clip and the PSU turned on fine apparently.
I have tried unplugging everything but the motherboard and CPU power cables, the front panel connectors from the case (a Thermaltake V4), the CPU fan, one stick of RAM and the videocard (no onboard video on this motherboard). The computer remained dead through this test, still no lights or beeps (although I'm not sure this motherboard has a built-in speaker).
I'm no expert, but I seem to have narrowed it down to some options, in order of likelihood:
1 - dead motherboard
2 - faulty power button on my case (although I do remember that, before the storm, I used to get lights from the phase LEDs when I switched the PSU on, before actually pressing the power button on the case... I don't get those lights anymore.)
3 - PSU not supplying the correct voltage on the motherboard connector (is there any way I could test this? I do not own a multimeter... Besides, is that possible to happen, even though it powered up just fine during the paper clip test?)
Could any good soul shed me some light on this? Thanks a lot!
25 answers Last reply
More about investigating dead
  1. I wouldn't focus on the power button as much...storms usually don't hurt mechanical switches. A dead motherboard is a possibility...but also....just because the PSU turns on doesn't mean it is outputting correctly. A multimeter would be very useful at this point. However a PSU swap will also tell you if it's the PSU.
  2. jay32267 said:
    I wouldn't focus on the power button as much...storms usually don't hurt mechanical switches. A dead motherboard is a possibility...but also....just because the PSU turns on doesn't mean it is outputting correctly. A multimeter would be very useful at this point. However a PSU swap will also tell you if it's the PSU.


    I'd say PSU or Motherboard, if the PSU is outputting power at all over the 24-pin you would see lights on the motherboard. It's most likely the board shorted during a surge or something.
  3. jay32267 said:
    I wouldn't focus on the power button as much...storms usually don't hurt mechanical switches. A dead motherboard is a possibility...but also....just because the PSU turns on doesn't mean it is outputting correctly. A multimeter would be very useful at this point. However a PSU swap will also tell you if it's the PSU.

    I have been thinking about buying a multimeter for some time now, mostly to work on my house wiring. Would a regular multimeter, such as the one I'd buy to do home jobs, also help me figure out what's wrong with my computer? Or would I have to be looking at a specialized multimeter for those lower voltages?
  4. Daguin said:
    jay32267 said:
    I wouldn't focus on the power button as much...storms usually don't hurt mechanical switches. A dead motherboard is a possibility...but also....just because the PSU turns on doesn't mean it is outputting correctly. A multimeter would be very useful at this point. However a PSU swap will also tell you if it's the PSU.

    I have been thinking about buying a multimeter for some time now, mostly to work on my house wiring. Would a regular multimeter, such as the one I'd buy to do home jobs, also help me figure out what's wrong with my computer? Or would I have to be looking at a specialized multimeter for those lower voltages?


    If you buy a good high quality multimeter that can be set for lower voltages your fine.
  5. jacobweaver800 said:
    Daguin said:
    jay32267 said:
    I wouldn't focus on the power button as much...storms usually don't hurt mechanical switches. A dead motherboard is a possibility...but also....just because the PSU turns on doesn't mean it is outputting correctly. A multimeter would be very useful at this point. However a PSU swap will also tell you if it's the PSU.

    I have been thinking about buying a multimeter for some time now, mostly to work on my house wiring. Would a regular multimeter, such as the one I'd buy to do home jobs, also help me figure out what's wrong with my computer? Or would I have to be looking at a specialized multimeter for those lower voltages?


    If you buy a good high quality multimeter that can be set for lower voltages your fine.

    How much would I be looking to spend?
    I have found one with the following configs:

    LCD display 3 1/2 digits/2000
    DC voltage 200m/2000m/20/200/600V
    AC voltage 200/600V
    DC current 200μ/2000μ/20m/200m/10A
    Resistance 200/2000/20k/200k/2000kΩ
    Basic precision 0,8%

    Would that cut it?
  6. Daguin said:
    jacobweaver800 said:
    Daguin said:
    jay32267 said:
    I wouldn't focus on the power button as much...storms usually don't hurt mechanical switches. A dead motherboard is a possibility...but also....just because the PSU turns on doesn't mean it is outputting correctly. A multimeter would be very useful at this point. However a PSU swap will also tell you if it's the PSU.

    I have been thinking about buying a multimeter for some time now, mostly to work on my house wiring. Would a regular multimeter, such as the one I'd buy to do home jobs, also help me figure out what's wrong with my computer? Or would I have to be looking at a specialized multimeter for those lower voltages?


    If you buy a good high quality multimeter that can be set for lower voltages your fine.

    How much would I be looking to spend?
    I have found one with the following configs:

    LCD display 3 1/2 digits/2000
    DC voltage 200m/2000m/20/200/600V
    AC voltage 200/600V
    DC current 200μ/2000μ/20m/200m/10A
    Resistance 200/2000/20k/200k/2000kΩ
    Basic precision 0,8%

    Would that cut it?


    It looks like it would work, but I've never used one before soo yeah...
  7. Daguin said:
    jacobweaver800 said:
    Daguin said:
    jay32267 said:
    I wouldn't focus on the power button as much...storms usually don't hurt mechanical switches. A dead motherboard is a possibility...but also....just because the PSU turns on doesn't mean it is outputting correctly. A multimeter would be very useful at this point. However a PSU swap will also tell you if it's the PSU.

    I have been thinking about buying a multimeter for some time now, mostly to work on my house wiring. Would a regular multimeter, such as the one I'd buy to do home jobs, also help me figure out what's wrong with my computer? Or would I have to be looking at a specialized multimeter for those lower voltages?


    If you buy a good high quality multimeter that can be set for lower voltages your fine.

    How much would I be looking to spend?
    I have found one with the following configs:

    LCD display 3 1/2 digits/2000
    DC voltage 200m/2000m/20/200/600V
    AC voltage 200/600V
    DC current 200μ/2000μ/20m/200m/10A
    Resistance 200/2000/20k/200k/2000kΩ
    Basic precision 0,8%

    Would that cut it?


    It looks like it would work, but I've never used one before soo yeah...
  8. Just get a basic cheap multimeter for like 20$. That will work for anything you need. They are handy to have around. What Daguin posted is more than enough.

    The main things you need are DC Voltage, AC Voltage and resistance.
  9. Went and bought myself a multimeter for cheap. I've just tested all pins from the 24pin ATX connector (motherboard power) and also from the 8pin ATX connnector (CPU power), and all of them stayed within the correct range of voltage. The "power good" pin (pin number 8 on the 24pin connector) gave me a voltage of 4.95v which I suppose is fine too.
    It seems very likely that I've got a dead motherboard. Is just there any way I could try to power up my PC by shorting some wires, instead of using the power up button on the case? That is, while having the PSU connected to the motherboard through the 24pin connector. Just to rule out completely the possibility of problems with the powering up mechanism (either a mechanical failure from the power button on the Thermaltake V4 or a bad connection between pins number 16 (PS-ON) on the motherboard and the PSU?
  10. Yes, you can short the 2 pins on the front panel header that connect to the front panel power switch. The front panel header is usually on the very bottom of the motherboard. Disconnect the 2 wires that go to the front panel power switch and use a metal tipped screwdriver to short across the 2 pins for a second or so. Your motherboard manual will help identify the correct pins.
  11. mjslakeridge said:
    Yes, you can short the 2 pins on the front panel header that connect to the front panel power switch. The front panel header is usually on the very bottom of the motherboard. Disconnect the 2 wires that go to the front panel power switch and use a metal tipped screwdriver to short across the 2 pins for a second or so. Your motherboard manual will help identify the correct pins.

    Thanks! I tried it and still nothing.
    Guess I'm off to find a new 1155 board.
  12. Daguin said:
    mjslakeridge said:
    Yes, you can short the 2 pins on the front panel header that connect to the front panel power switch. The front panel header is usually on the very bottom of the motherboard. Disconnect the 2 wires that go to the front panel power switch and use a metal tipped screwdriver to short across the 2 pins for a second or so. Your motherboard manual will help identify the correct pins.

    Thanks! I tried it and still nothing.
    Guess I'm off to find a new 1155 board.


    Yeah, your boards fried worse than a burnt steak on a grill.
  13. I've just stumbled upon another problem and thought: why not recycle this same thread?
    I bought an Asus motherboard, specifically a P8Z77-V Pro, but I can't seem to get my machine to boot. I keep getting that constant red light from the DRAM OK LED. I've tried holding down the MEM!OK button dozens of times. What it did was make the LED flash, at first slower and then faster, and the system turned off and back on a couple of times. But it always eventually came back to a constant red LED light, with still no video or booting. I've also tried flashing the BIOS to the news version with BIOS Flashback feature, and I've also removed the BIOS battery to try to reset it.
    Could it be a compatibility error? My RAM is consisted of two sticks of 4GB Markvision RAM: 1333MHz, CL9, 1.5v (BMD34096M1333C9).
  14. Yeah compatibility is a good guess. It doesn't look like markvision is still around so don't know where to find compatibility info motherboard wise. You couldn't get same model of mobo you used to have?
  15. Sedivy said:
    Yeah compatibility is a good guess. It doesn't look like markvision is still around so don't know where to find compatibility info motherboard wise. You couldn't get same model of mobo you used to have?

    Here in Brazil all 1155 boards are out of stock, so the only way was to look for second-handers. Didn't find any GA-Z68X-UD3 boards for sale, so I went for this Asus.
    The P8Z77-V Pro advertises its compatibility with 1333MHz memory on the box. So shouldn't compatibility be a non-brainer? On the other hand I've heard that Z77 chipsets are picky with "generic" sticks. Would two sticks of Corsair Vengeance Pro 4GB 1600MHz CL9 be compatible?
  16. When you pick a board, always first check its memory qvl list, and then pick a memory off of it so that you're absolutely certain of compatibility.
    For example, for P8Z77-V Pro, https://www.asus.com/Motherboards/P8Z77V_PRO/HelpDesk_QVL/ check all the lists off with the links there, and pick only memory that's on it. The timings are important, not just the overall clock, so merely being 1333MHz doesn't really guarantee compatibility.
  17. Sedivy said:
    When you pick a board, always first check its memory qvl list, and then pick a memory off of it so that you're absolutely certain of compatibility.
    For example, for P8Z77-V Pro, https://www.asus.com/Motherboards/P8Z77V_PRO/HelpDesk_QVL/ check all the lists off with the links there, and pick only memory that's on it. The timings are important, not just the overall clock, so merely being 1333MHz doesn't really guarantee compatibility.

    Today I borrowed a stick of Corsair Vengeance Pro 4GB 1600MHz CL9 1.5v RAM (CMY8GX3M2A1600C9R) from a friend and tested it on all 4 slots, with no results. Looking at the QVL (http://dlcdnet.asus.com/pub/ASUS/mb/LGA1155/P8Z77-V_PRO/P8Z77-V-PRO-memory-QVL.pdf?_ga=2.267313102.1510487523.1518745592-1963262291.1518571168) I notice that specific model of Vengeance memory my friend owns is not on the list (neither are my Markvision sticks). Does that mean the Vengeance Pros he owns really are not compatible and the fact that my PC didn't boot with one stick of that RAM still doesn't discard the possibility of it simply being due to a compatibility issue and not a MoBo malfunction?
  18. It doesn't discount the possibility of a simple compatibility issue. Only if you test with something off that list and it doesn't work would I suspect a mobo issue. That doesn't mean it couldn't be your mobo, but less likely to be in my opinion. This is why repair shops are useful. They'll have tons of memory sticks around to try things with.
    Also, there might be a way to make that memory compatible with your board by fiddling with voltage or clock and timings, but I don't know enough about it to recommend doing this or to give you a walkthrough on how. Technically based on its advertised timings and voltage, there are similar memories on there that work but memory/mobo compatibility can be really fiddly.
  19. Daguin said:
    Sedivy said:
    When you pick a board, always first check its memory qvl list, and then pick a memory off of it so that you're absolutely certain of compatibility.
    For example, for P8Z77-V Pro, https://www.asus.com/Motherboards/P8Z77V_PRO/HelpDesk_QVL/ check all the lists off with the links there, and pick only memory that's on it. The timings are important, not just the overall clock, so merely being 1333MHz doesn't really guarantee compatibility.

    Today I borrowed a stick of Corsair Vengeance Pro 4GB 1600MHz CL9 1.5v RAM (CMY8GX3M2A1600C9R) from a friend and tested it on all 4 slots, with no results. Looking at the QVL (http://dlcdnet.asus.com/pub/ASUS/mb/LGA1155/P8Z77-V_PRO/P8Z77-V-PRO-memory-QVL.pdf?_ga=2.267313102.1510487523.1518745592-1963262291.1518571168) I notice that specific model of Vengeance memory my friend owns is not on the list (neither are my Markvision sticks). Does that mean the Vengeance Pros he owns really are not compatible and the fact that my PC didn't boot with one stick of that RAM still doesn't discard the possibility of it simply being due to a compatibility issue and not a MoBo malfunction?
  20. Daguin said:
    Greetings everyone.
    My computer has stopped turning on after a storm. No lights, beeps, nothing.
    Configs are as follows: i5 2500k, GTX 760, Gigabyte GA-Z68X-UD3-B3 motherboard, 2 sticks of 1333MHz 4GB RAM and a Corsair TX650M PSU.
    I have tested the PSU by the method of shorting out the green and black wire connectors with a paper clip and the PSU turned on fine apparently.
    I have tried unplugging everything but the motherboard and CPU power cables, the front panel connectors from the case (a Thermaltake V4), the CPU fan, one stick of RAM and the videocard (no onboard video on this motherboard). The computer remained dead through this test, still no lights or beeps (although I'm not sure this motherboard has a built-in speaker).
    I'm no expert, but I seem to have narrowed it down to some options, in order of likelihood:
    1 - dead motherboard
    2 - faulty power button on my case (although I do remember that, before the storm, I used to get lights from the phase LEDs when I switched the PSU on, before actually pressing the power button on the case... I don't get those lights anymore.)
    3 - PSU not supplying the correct voltage on the motherboard connector (is there any way I could test this? I do not own a multimeter... Besides, is that possible to happen, even though it powered up just fine during the paper clip test?)
    Could any good soul shed me some light on this? Thanks a lot!
  21. Take a look at the capacitors on the MB if they are 'puffed up' and not flat your MB needs to be replaced.
  22. Take a look at the capacitors on the MB if they are 'puffed up' and not flat your MB needs to be replaced.
  23. fury1138 said:
    Take a look at the capacitors on the MB if they are 'puffed up' and not flat your MB needs to be replaced.


    not necessarily, my old MB has 3 blown capacitors on the line to the CPU and it still works fine years after they died.
Ask a new question

Read More

Light Computers Motherboards