Randomly will and won't boot

I've ran into quite a few problems recently. I don't know if this is new or something related to a problem I've been having for a while so I'll probably have a lot more details than are needed.

Earlier today I tried to use a capture device to record something from a game system. I already had the drivers installed but for some reason it went through the whole "found new hardware" "installing drivers" anyway. I know it originally said not to let it install the drivers that way but I figured that since they were already installed from the cd it was no big deal. I let it install and when I tried to use it I got the blue screen.

After that I uninstalled and reinstalled them but I still got a blue screen when I tried to use it. Eventually I gave up on it and went to other things. Still after a while I kept crashing. Often times after crashing I would have to restart several times because it just wouldn't boot.

After a while I just decided to reformat and install a new copy of Vista. It got to "expanding files" where it sat at 0% for three hours and I powered off manually. When I tried to power back on it didn't load. No POST and the monitor showed no signs of getting a signal. No matter how many times I retried it nothing came up. I was getting two quick beeps from the bios.

I took it apart and put it back together piece by piece. I found that if I have a stick of memory in the second slot I get two quick beeps but if I don't I only get one. Either way though I still get nothing when I power on.

This is similar to a problem I've been having a while now (years actually) where sometimes it will just stop booting for a couple days, no POST, no beeps, nothing. After a few days it will start working file again as if nothing happened. It usually happens during the summer so my first assumption when it happens is overheating. It has happened a couple times during the winter however and even after a couple days of being unplugged it still doesn't start (until a couple of more days later).

This has happened with three different video cards and various sticks of RAM. I've taken it in a couple times but each time it started working on the way there. They've tweaked a couple things and made some suggestions but it still keeps coming back. I'm not sure if this problem is related to the problem I'm having now, but it's similar so I figured it was best to include it.

The computer is custom built. I'm not positive as to what kind of bios it uses but I do know the motherboard is Intel.

So I'm at a dead end right now and any help would be greatly appreciated.
Thanks in advance.

 

It would be useful to know what sort of BIOS you have got. It normally tells you on the first screen as you boot up.

Anyhow from your description I would first have suspected a duff RAM stick aas 2 hort POST beeps is a memory falure if you have an AMI BIOS. My second suggestion, as you say this happens with various RAM chips is you have a flaky power supply with possibly one of the output voltages being marginal. Try a different PSU if you can get hold of one and see if that makes a difference.

 

Thanks a lot for your help. Okay, a few more things.

Firstly I can't check the BIOS because the monitor just doesn't come on. I can tell it's loading (now) but nothing is displayed on screen.

I just installed a fresh copy of Vista. I started as soon as the crashes started, halfway through, the screen wouldn't come on so I just left it. It worked briefly this morning and I managed to finish the new install (complete reformat). After that it got shut off and won't come back on (display anything on screen).

As for the memory, I have four slots for RAM. If there is anything in slot 2 I will get the 2 short beeps. However if it is inserted into any of the other slots there is only one beep and I can tell the computer is booting. If left for a minute the power button must be held down to turn it off, showing that Windows is at loading in the background. Still the monitor never comes on and if turned on manually I get the "no signal input" message.

I'm currently talking to a friend about getting another power supply to see if that is the issue. Still, it is a pretty powerful computer and most spare power supplies I could get a hold of wont be strong enough. If I have to buy a new one I don't want to do so unless I'm sure that is the problem.

Like I say, I'm pretty sure this has happened previous years and the most common theory was that the cpu was overheating (either because the heatsink was dirty or the goo around the chip had hardened). Today was a rather cool day and the computer was left unplugged for ten hours, so I doubt it's overheating, but since that's what people thought earlier I figure it's worth a mention. If the CPU was overheating enough to cause no display, would Windows still be able to boot?

I think when I first posted this I was having two problems, a software issue (caused by bad drivers and fixed with the reformat), and the hardware issue I've had for years now. Although I already said I don't think it's caused by overheating, it should be noted that 95% of the time when it does this it's during the summer, usually beginning on hot days. Then, as previously mentioned, a week or so later it just starts working again as if nothing was wrong (even if previous days were much cooler).

 

Thanks a lot for your help. Okay, a few more things.

Firstly I can't check the BIOS because the monitor just doesn't come on. I can tell it's loading (now) but nothing is displayed on screen.

I just installed a fresh copy of Vista. I started as soon as the crashes started, halfway through, the screen wouldn't come on so I just left it. It worked briefly this morning and I managed to finish the new install (complete reformat). After that it got shut off and won't come back on (display anything on screen).

As for the memory, I have four slots for RAM. If there is anything in slot 2 I will get the 2 short beeps. However if it is inserted into any of the other slots there is only one beep and I can tell the computer is booting. If left for a minute the power button must be held down to turn it off, showing that Windows is at loading in the background. Still the monitor never comes on and if turned on manually I get the "no signal input" message.

I'm currently talking to a friend about getting another power supply to see if that is the issue. Still, it is a pretty powerful computer and most spare power supplies I could get a hold of wont be strong enough. If I have to buy a new one I don't want to do so unless I'm sure that is the problem.

Like I say, I'm pretty sure this has happened previous years and the most common theory was that the cpu was overheating (either because the heatsink was dirty or the goo around the chip had hardened). Today was a rather cool day and the computer was left unplugged for ten hours, so I doubt it's overheating, but since that's what people thought earlier I figure it's worth a mention. If the CPU was overheating enough to cause no display, would Windows still be able to boot?

I think when I first posted this I was having two problems, a software issue (caused by bad drivers and fixed with the reformat), and the hardware issue I've had for years now. Although I already said I don't think it's caused by overheating, it should be noted that 95% of the time when it does this it's during the summer, usually beginning on hot days. Then, as previously mentioned, a week or so later it just starts working again as if nothing was wrong (even if previous days were much cooler).

 

Well two things. As you get the PC to boot as long as nothing is in slot 2 - it strongly suggests something wrong with that particular slot. I assume you have checked to see if nothing is trapped in the slot causing a poor contact.

As for the lack of anything on the monitor that may be due to an incorrect video driver (or corrupt driver) loading. If you PC has a floppy drive try booting from a bootable floppy (a win 98 floppy would do) to see if anything appears on screen in old fashioned DOS mode. If it does then it may well be a driver problem if not I'll need a further think.