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My bios will not POST, my computer won't display, no beeps?

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April 14, 2011 1:35:59 AM

I just installed a new CPU fan and heatsink (http://www.newegg.com/Product/Product.aspx?Item=N82E168... to be precise), and after installing it I am getting the problems in the title. All of the lights and fans come on, but I am greeted with a black screen. It is probably notable to also point out, I can't just click the power button to turn it back off. I have to hold it for 10 seconds, which I only ever seem to need to do in the OS. So anyways, I guess I should specify stuff more. I am using a P7P55 LX Asus motherboard, an 850W powersupply, 1156 i7 2.8 GHz (Which was overclocked to a modest 3.0 GHz), 500 GB HDD, a 4000 series Radeon GPU, and I have 3 case fans. I'm sure a lot of that was unnecessary info, but yeah, can't be to specific. :D  Anyways, after I installed the new heatsink and fan, I have been getting those issues. I have tried resetting CMOS, replacing the stock fan, reseating RAM, etc. But nothing is working. Did I by chance damage the motherboard during the installation? Is the any surefire way to tell?
a c 299 Ĉ ASUS
a c 1097 V Motherboard
April 14, 2011 7:02:04 AM

Sounds like it is loading the OS but not displaying to the screen, this points to a GPU problem. Try reseating the GPU and/or try it in a different computer if possible.
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a b Ĉ ASUS
a c 156 V Motherboard
April 14, 2011 7:32:07 AM

No post, no beeps? It isn't loading the OS.

Make sure that all the power cables (main, CPU, and PCIe) are connected.

A quick check to determine if the video card may be the problem - pull the video card and boot. Assuming you have the small system (case) speaker installed, you should hear something like one long and 2 or 3 short beeps telling you that the system detected something wrong with your video card (like it is missing :) ).

Silence indicates that the system is not even trying to POST.

The following is an expansion of my troubleshooting tips in the breadboarding link in the "Cannot boot" thread.

I have tested the following beep patterns on Gigabyte, eVGA, and ECS motherboards. Other BIOS' may be different, but they all use a single short beep for a successful POST.

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 once you are finished.

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...

A way that might be easier is to use the main power plug. Working from the back of the plug where the wires come out, use a bare paperclip to short between the green wire and one of the neighboring black wires. That will do the same thing with an installed PSU. It is also an easy way to bypass a questionable case power switch.

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, long single beeps, or series of short beeps indicate a problem with the memory. If you get short beeps verify that the memory is in the appropriate motherboard slots.

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.
At this point, if the system doesn't work, it's either the video card or an inadequate PSU. Or rarely - the motherboard's PCIe interface.

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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a b V Motherboard
April 14, 2011 9:31:43 AM

The first thing to check is to make sure that your graphics card is seated correctly, it is common to dislodge the graphics card when mucking about inside the computer. Similarly check the memory is seated correctly. The best way to check the seating of these components is to remove and refit them. If this does not work the try temporarily connecting the old CPU fan into the motherboard CPU fan connector. The motherboard checks for a working CPU fan and will not start up if it thinks one is not connected. Clearing the CMOS to remove the overclock may be a good idea.
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April 14, 2011 3:18:42 PM

Actually, I don't know if my chassis speaker is even connected to the motherboard properly. What is a header usually labeled on a motherboard for a chassis speaker? Do motherboards always have output for a speaker?
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April 14, 2011 3:19:54 PM

Because I haven't actually had it connected until this problem came about....
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April 15, 2011 2:35:19 PM

Okay, well, I made sure and I have everything connected correctly with the speaker. I have reseated everything in different combinations, tried a new power supply, everything. Nothing has helped. Is it safe to assume I just damaged the board while moving it to place the heatsink and fan?
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a b V Motherboard
April 15, 2011 4:46:52 PM

At this point I would remove the new heatsink and fan, remove and refit the CPU and try again.
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April 15, 2011 5:00:58 PM

Is the fan running?
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