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Computer won't start.

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  • Asus
  • Computer
  • Intel
  • Motherboards
Last response: in Motherboards
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October 16, 2010 4:42:41 AM

Hello, I have an ASUS P5G41C-M LGA 775 Intel G41 HDMI Micro ATX Intel Motherboard with an Intel E6500 "Wolfdale" 2.93 GHz LGA 775 CPU. The issue is that when I completed the new bundle with an old Compaq Presario SR2710NX, I connected, plugged in the power and pressed the power buton...no boot or POSt at all. No fans at all as a matter of fact. What is wrong?

More about : computer start

a b Ĉ ASUS
a b å Intel
a c 156 V Motherboard
October 16, 2010 4:52:00 AM

Don't know.

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. We spent a lot of time on this. It should find most of the problems.

If not, continue.

I have tested the following beep patterns on Gigabyte, eVGA, and ECS motherboards. Other BIOS' may be different.

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.

Make sure you plug the CPU power cable in. The system will not boot without it.

I always breadboard a new build. It takes only a few minutes, and you know you are putting good parts in the case.

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:
Running fans and drives and motherboard LED's do not necessarily indicate a good PSU. In the absence of a single short beep, they also do not indicate that the system is booting.

At this point, you can sort of check the PSU. Try to borrow a known good PSU of around 550 - 600 watts. That will power just about any system with a single GPU. 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.

This will be a little different if you have integrated graphics.

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.
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October 16, 2010 5:02:33 AM

Nope. I now it is not the PSU that is bad. It has worked before and I tested it. When I push the case power buttn to turn everything on, ther is nothing...absolutly nothing. Could it be a ground?
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a b Ĉ ASUS
a b V Motherboard
October 16, 2010 9:05:23 AM

Are you sure you connected the power button terminals to the correct header on the motherboard ?
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October 16, 2010 10:04:22 AM

You have to test it now, it could be something like loose cables, power button, PSU, RAM, Motherboard, GFX Card.
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October 16, 2010 7:54:49 PM

Here was the dea;. The connector was not grounding the unit. I have to touch the power real and the ground real to get it started.

Now I have another issue: after POST, I get the windows loading signal, but then a BSOD flashes and theunit POSTs again. Also, when I overclock the unit does not POST.
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