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Problems with even starting my computer

Last response: in Systems
January 20, 2011 4:36:49 AM

Hey everyone. A few months ago, I built this fantastic tower. It had been working fine, and I had added a few parts to no consequence. However, recently, I've been having some major problems with my computer.

I am not sure if this is relevant, but a week or so prior to the major problems I removed the "SystemTool 2011" virus. Just thought I'd say that.

Yesterday, I started to have trouble with my computer. Funny enough, I was gaming, like most nights, and I started to lag really hard in Starcraft 2. I changed graphic settings to low, and I lagged out of both the games I played. (I usually play on Ultra). I restarted the computer, and the problems persisted. So, I opened up my case to take a look at it.

After opening it up, I took a look and took a look at my RAM (to get the model and what not - also not sure if it is relevant). Put everything back to how it was, and all of a sudden my computer started to have more problems. I booted my computer, and the first time, I was able to log in and everything. Soon after, it shut off. The next few times I attempted to boot, it shut off quite quickly. Again, I looked at it.

However, now, the computer will turn on, but, no display will go to the monitor now. I haven't changed any connectors or anything since it has been working. The computer will turn on, all the fans, lights, hard drive, CPU fan, all seems to be working and spinning. But, as stated, no display will appear. After a few minutes, the computer shuts off.

Does anyone have any idea of what is happening here?

Antec Nine Hundred Gaming Case
lost the box for the mobo - I can't find the model
ATI Sapphire Radeon HD 5670
Kingston ValueRAM 4GB PC3-10600 DDR3 Dual Channel Kit (2 x 2GB)
Corsair VX 550W PSU
Intel Core™ i3 Processor 530 2.93GHz w/ 4MB Cache, HD Graphics
HDD is some old 130GB Seagate Barracuda

Any type of help would be immensely appreciated.

More about : problems starting computer

a c 122 B Homebuilt system
January 20, 2011 4:56:16 AM

Work systematically through our standard checklist and troubleshooting thread:
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, 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.

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.

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.
January 21, 2011 1:30:38 AM

I performed everything that I could in the guide, excluding analyzing the system speaker, due to my lack of one. Also, it is worth noting that the computer did work previously; so I at least know my configuration works.
a c 122 B Homebuilt system
January 22, 2011 12:46:57 PM

If you have a system that does not work, you really, really, REALLY need the little speaker.

Either that, a large parts bin, or a fair amount of money and time to randomly change parts.
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