Same issue with old and new computer, no boot no post

Hi all,

Well this is complicated so i'll go step by step.

Several weeks ago my computer was having an intermittent problem were it would freeze (idle or busy) I would manually restart it and then it wouldn't boot at all, no boot no post. I've tried different cables, removed the memory, unplug one device at a time (from the back panel) nothing helped.

I took it to a shop nearby and the tech couldn't find any issue with it. It booted right up, the PSU and HD's were both positive after tests so I took it home. It booted right up too so I proceeded to update the Bios. That seemed to have had an effect because for a period of two weeks after that update (I was 6 updates behind) it didn't freeze at all, every time I needed to reboot it would do so flawlessly.

Then, last week, it started again. I decided to upgrade most of the hardware, I then installed Win7 as well as many of the programs I use and so far everything was cool. I even play a bit of Starcraft 2 and encode some video. All was fine.

Then yesterday the same problem occurred. It froze for no particular reason because it was idle at the time and when I tried to reboot it nothing happened. Again I tried several combination of new cables, removing memory as well as unplug all back panel devices and peripherals to no vail.

I took it back to the shop yesterday and now I just hung up with the tech there and guess what he told me. Everything is fine, it booted right up and all parts are positive after testing was done.

Thing is, when I say it doesn't boot something does boot. As soon as I power it on all fans will turn on but nothing else, the hard drives won't boot. It's as if the power stopped at the fan (or was necessary enough for the fans but stops there).

Also, I have my computer plugged into a ups which is an APC XS 1300w, could it be possible that it doesn't supply enough power to the computer?

I'm quite beside myself with this issue that seems to follow me whatever I do.

Any ideas or comments?

If you need more info go ahead and ask.



Old specs
-Asus M4A78-T
-AMD Phenom 2 9950
-2x 2gb DDR3 Kingston memory sticks
-Asus ATI EAH4850
-Antec TruePower 650 watts
-1 WD 80gb SATA2
-1 Maxtor 250gb IDE
-1 1TB USB2 External drive
-1 LG external DVD drive (not turned on most of the time)
-1 LG monitor W2353V

New Specs (bold is new)
-Asus M4A88TD-V EVO /USB3
-AMD Phenom 2 x4 945
-Zalman CPU Fan CNPS9500
-2x 2gb DDR3 Kingston memory sticks
-Asus ATI EAH 5750
-Antec TruePower 650 watts
-1 WD 80gb SATA2
-1 WD 1TB Caviar SATA3
-1 1TB USB2 External drive
-1 LG external DVD drive (not turned on most of the time)
-1 LG monitor W2353V
11 answers Last reply Best Answer
More about same issue computer boot post
  1. Did you recycle the PSU from the old system into the new system? Sounds an awful lot like a flaky PSU that "dies" when it gets hot. These things do wear out. Do you have another PSU that you swap into the new rig to check it out?
  2. Indeed I recycled the PSU.

    Got back fomr the shop and it turns out that on my new MOBO I needed to plug a 8pin connector to it, I plug only a 4-pin. That one kinda damaged and must've cause short circuit in the old board. Too bad it wasn't diagnose earlier as I would have save 500$.

    Now the reason why the new board was able to function with power from only a 4pin connector remains a mystery.

    That's the kind of question I'd like an answer to.


  3. Normally you can plug the 4 pin adapter into the correct half of the 8pin plug and it will work fine.

    One other possibility is that your UPS isnt getting enough power to stay fully charged. Next time it happens, try plugging your PC into a surge protector instead of the UPS. If it then works you know you have either a bad UPS or bad building power. Maybe you are on a circuit with alot of other devices and the amperage you get isnt enough for that large PSU to keep the battery charged, or maybe the battery is old. They only last a few years normally.
  4. You can run 4 or 8 if you dont overclock 4 is plenty.
  5. The 4 pin connector vs. 8 pin connector is rather moot. As daship and dndhatcher pointed out, unless OCing, the 4 pin connector works fine. Seems you were having the same problem with the old config as you are having with the new config. The least common denominator and likely culprit of the instability is the PSU. Good luck!
  6. Thanks guys

    No I don't OC so this is not the issue. On the 4-pin connector one of the end was exposed due to some of the plastic that was missing. I guess it must've melted or was cracked somehow. It must have cause short circuit from time to time, which is likely why my computer would freeze for no reason.

    Thankfully that PSU included a 8-pin connector so I don't have to buy a new one...yet.

    As for my UPS is is still new and such a powerhouse that I believe it very unlikely that it doesn't keep up, especially since my rig uses about 350 idle and maybe 400 when it is busy.

    Still, the thought occurred to me yesterday that if it happens again I should try plugging the computer directly into the power bar.

    So far though it's all good with the 8-pin connection.


  7. slave1 said:

    As for my UPS is is still new and such a powerhouse that I believe it very unlikely that it doesn't keep up, especially since my rig uses about 350 idle and maybe 400 when it is busy.
    UPS has plenty of wattage. If the battery is new then thats not likely an issue. I am more concerned that the UPS isnt getting enough amperage out of the wall socket to stay fully charged.

    I guess we should go back to UPS 101. Do you have a power bar plugged into the UPS? I hope not. If you do then that is likely to be your problem.
  8. Nope, one power bar is in one outlet and the UPS in another.

    Thanks for your suggestion though.

  9. Best answer
    Work through our standard checklist and troubleshooting thread:
    I mean work through, not just read over it.

    Breadboard - that will help isolate any kind of case problem you might have.

    Breadboard with just motherboard, CPU & HSF, case speaker, and PSU. You do have a case speaker installed, right? If not, you really, really need one. If your case or motherboard didn't come with a system speaker, you can buy one here:

    You can turn on the PC by momentarily shorting the two pins that the case power switch goes to.

    You should hear a series of long, single beeps indicating memory problems.
    Silence indicates a problem with (in most likely order) the PSU, motherboard, or
    CPU. Remember, at this time, you do not have a graphics card installed so the load on your PSU will be reduced.

    If no beeps:
    At this point, you can sort of check the PSU. Try to borrow a known good PSU. If you cannot do that, use a DMM to measure the voltages. Measure between the colored wires and either chassis ground or the black wires. Yellow wires should be 12 volts. Red wires: +5 volts, orange wires: +3.3 volts, blue wire : -12 volts, violet wire: 5 volts always on. Tolerances are +/- 5% except for the -12 volts which is +/- 10%.

    The gray wire is really important. It should go from 0 to +5 volts when you turn the PSU on with the case switch. CPU needs this signal to boot.

    You can turn on the PSU by completely disconnecting the PSU and using a paperclip or jumper wire to short the green wire to one of the neighboring black wires.

    This checks the PSU under no load conditions, so it is not completely reliable. But if
    it can not pass this, it is dead. Then repeat the checks with the PSU plugged into the computer to put a load on the PSU.

    If the system beeps:
    If it looks like the PSU is good, install a memory stick. Boot. Beep pattern should
    change to one long and several short beeps indicating a missing graphics card. Silence or long single beeps indicate a problem with the memory.

    Insert the video card and connect any necessary PCIe power connectors. Boot. At this point, the system should POST successfully (a single short beep). Notice that you do not need keyboard, mouse, monitor, or drives to successfully POST.

    Now start connecting the rest of the devices starting with the monitor, then keyboard and mouse, then the rest of the devices, testing after each step. It's possible that you can pass the POST with a defective video card. The POST routines can only check the video interface. It cannot check the internal parts of the video card.
  10. Pretty thorough, thanks JSC ;)
  11. Best answer selected by slave1.
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