I have a prebuilt I was looking to upgrade but found that to quickly be a big mistake... I have a GeForce GTX 580, Corsair TX750 PSU, M4N68T-M V2 motherboard, and an AMD Phenom II x4 840 as my main components. The only issue is that I can't get any picture. At first, I was thinking its the graphics card but I just recently "unbnet" the pins on my CPU after installing it wrong but when I turn the computer on, it works fine. The other thing is my graphics card doesn't fit the case properly and the tab of the graphics card is caught on the case so it won't seat fully. I'm thinking its the main issue but specifically, the shorter side of the graphics card pins are shown, about half a millimeter. Is this the reason that I most likely don't have display or something else I'm missing? Thanks!
Actually, I don't remember why I took out the CPU but it originally came installed when I got it prebuilt. I got a replacement motherboard because my old one was defective but there's those risen holes on the case that work as standoffs. Everything else on it works except video.
The onboard should disable with the discrete card in the PCIe slot but should work if you do not have the card in. If it does then we can safely say it is a problem with the card both being nvidia should display on the same drivers.
No signal means that there is nothing coming from the computer to the monitor, it is a monitor message and does not come from the computer itself. You have not mentioned any beebs so I am presuming there is no case speaker installed and that the computer is not finishing post which can be bad CPU or bad motherboard. Last try without the card using the onboard, with the power off pull the motherboard battery out for a few seconds to reset BIOS, if it still does not display then the wrong insertion damaged both or one or the other!
The computer has an onboard speaker, there are no beeps, and does not start/successfully finish POST. The issue is I don't have much of a way to diagnose the issue since I don't have a power LED indicator to diagnose the problem. I just got the replacement motherboard so I doubt its that. Like I said, I've tried it with just the onboard video and still got the same message.
I doubt its the board, its from CyberPower (although manufacturered by Asus)
and they supposedly test their products before sending them out. I figured it was the processor as well but don't feel like spending the $100 when I don't even know if thats truly why I have no video....
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: http://www.cwc-group.com/casp.html
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.
Motherboard LED's mean very little. When on, all they are telling you is that the computer os plugged into a live power socket and the PSU is switched.
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 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.
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.