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PC appears dead - is my mobo to blame?

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September 3, 2010 6:32:38 PM

Hello,

so I put my comp to sleep last night and woke up this morning to find that first that there was no power running to the mouse or keyboard despite the system being powered up.

I rebooted

black screen.
No dos prompt or error
no mobo "beep" at startup

My question is, is my mobo to blame? or could this be something else? I built this comp myself so Im somewhat knowledgeable about troubleshooting.

also I had a raid 0 setup, if it is my mobo would it be possible for me to recover my data if I simply replace the motherboard with a new model of the same version?

Any suggestions or tips would be welcome. thanks
a b Ĉ ASUS
a c 103 V Motherboard
September 3, 2010 7:49:45 PM

First of all, I would start with pulling out all (yes, all) of your RAM. Then reboot, if you get the error beeps associated with no RAM detected, then we can assume (for now) that your mobo is still good.

Second, even if you didn't hear anything with no RAM installed, install the RAM modules one at a time and boot up. Do this until you've installed every module in every slot, alternating, of course.

As for the HDD question, yes. If you replace the mobo with the same model, you won't have to reinstall anything.
September 3, 2010 9:19:49 PM


Are there any fans HDD starting up?
Its possible that the Mobo is gone but i would change the PSU first from another system. Usually the mobo had a power good led around. If the power supply starts you can actually check the voltages on it. Its possible that the PSU is in protection mode (usually has a weird noise. Unplug all big consumers HDD CD-Roms and additional cards including video.

Need more info on this one .

Regards Sylma
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September 4, 2010 4:12:36 AM

many thanks to you both
I just swapped out the ram, no change, no beeps,

The sytems fans are coming on, the green light on the mobo is coming on, no video display, no noticable noise of accessing from the HDDs.

is it possible for a mobo to be burned out yet still have the green power light and power up system fans and ubs peripherals?
a b Ĉ ASUS
a c 103 V Motherboard
September 4, 2010 5:07:21 AM

Yes, it is possible for a motherboard to power up some circuits, but not all. It is still possible that your PSU crapped out and isn't supplying sufficient power to the mobo.

list your system components.
September 4, 2010 10:11:43 AM

hi there,

i would go for a mobo change but before that change the PSU .its a 50 50 chance. Try and source a voltmeter and measure voltages and see if any voltages are incorect.Google for ATX connector pinout

gluck
a b Ĉ ASUS
a c 156 V Motherboard
September 4, 2010 1:53:06 PM

Work through our standard checklist and troubleshooting thread:
http://www.tomshardware.com/forum/261145-31-read-postin...
I mean work through, not just read over it.

Breadboard - that will help isolate any kind of case problem you might have.
http://www.tomshardware.com/forum/262730-31-breadboardi...

Breadboard with just motherboard, CPU & HSF, case speaker, and PSU. 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.
http://www.youtube.com/watch?v=5FWXgQSokF4&feature=yout...

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.
September 7, 2010 2:45:45 AM

I had the same problem with my parents gateway. Motherboard light would come on but thats it. Changed the Power Supply and boom, fixed.
!