Computer Not Starting

Hi all. You guys have helped me with a lot of computer problems I've had before, I hope this time is no different

I usually leave my computer on at all times. This morning, when I woke up, I saw that the computer monitor was in sleep mode as it usually is, but when I shook the mouse or pressed the keyboard, nothing happened. I turned off the computer, and when I restarted it, there was no boot up, the monitor remained in sleep mode, while the computer was on.

I've had my computer for around 2 years now, I built it myself (3.0 prescott, p4p800 asus mobo, bfg 6800gt gfx card, etc...not sure what else maybe a factor). When I turn on the computer, everything is on, but it's as if it doesn't register with the monitor. Also, when I press the open buttons for both the dvd and cdrw drive, they don't open.

Any clues?

Thanks, much appreciated

Andy

 

Are the fans running when you hit the power?

Did you turn it off for an hour and try again?

From my experience, my guess is that one of 4 things had happened.

1. CPU overheated by means of a dead fan, or the heatsink got so much dust in it that it overheated. (This is unlikely, but I have seen it happen).

2. Your motherboard died. I have seen northbridge fans fail or get so full of dirt or the fan dies. I had this happen on an Asus A7V133, and that inturn caused the CPU fan to stop. Fortunately, I caught it in time. I replaced the northbridge fan, and all was good. (Very unlikely)

3. Graphics card too a crap. It will not post without a graphics card. (possible)

4. Your power supply died. 2 year old PSU's are known to die. I don't buy Antec anymore. (I would look at the PSU first, and I would bet your problem is there).

Don't be afraid to spend 100 bux or more on your PSU, it is money wells spent.

 

Thanks for the quick reply.

1. When I turn on the computer, all the fans are running, everything sounds fine. I have a xp-120 heatsink, and the fan is working. It maybe, a little dusty, but shouldn't be the cause of it.

2. I can't seem to locate the northbirdge fan. It may be the motherboard, but I see the greenlight on the bottom lit... I don't know if that means anything.

3. The fans on the graphics card are working, and the light is on. How do I check if it is the graphics card?

4. I'm pretty sure that it's not the PSU. I bought a brand new Enermax then, and it seems to be working.

Overall the computer sounds fine, lights are on where I usually see them, seems "on". Does the disk drives not ejecting provide any clues?

Thanks

 

My next step would be to re-seat the graphics card and try to boot, and then see if you can clear cmos and see if you can boot.

I suspect that either the motherboard or graphics card took a poop, based upon what you had told me.

If you have a multimeter, you can measure your 12v and 3v rails to see if they are within spec. Just because the fans are running does not mean there is enough power.

After that, you need to start swapping parts to find the culprit.

What kind of motherboard is it?

 

My motherboard is an Asus p4p800.

When you say reseat, does that mean taking it out and then putting it back in? Should I try turning on the computer with the graphics card out?

Thanks

Andy

 

In a word yes.

 

So, all is good now?

 

Nope...

I had a friend help me. He took out the parts one by one to see where the problem was. There was definitely power so it wasn't the power supply. After taking out a couple of parts and putting them back in, to no avail, we too out the cpu. The mobo (Asus p4p800) started saying "no cpu no cpu". Later with the cpu in, we heard an error message that sounded like "cpu error cpu error". The mobo would just kee repeating the error message until the computer was turned off.

There was still no boot up screen/sound.

 

I just had the same problem as you're describing. (I think) Computer would start but I'd never get the video. I had 3 long beeps. Code told me to first reseat the first ram memory stick. If that doesn't do it then you have to replace the ram. Worked like a charm for me.

Start your computer and count the number of beeps. You can find the beep codes listed on many web sites. I used this site.

http://www.technick.net/public/code/cp_dpage.php?aiocp_dp=guide_beep_codes

 

Nice link, but my computer doesn't emit any beeps when I turn it on... could it be the mobo that is screwed up?

 

You know, I have been doing this stuff for a long time, as an avid overclocker. In my experience it seems that anything will cause another to have problems.

Case in point, I had a PC that had terrible graphics problems upon startup. But it would work fine after everything would warm up. The PC had a 9700pro, or something, so, I put an old GF3 card to see if it worked, and indeed it did. Obviously, a bad graphics card, right? Nada. It turned out that the PSU was bad, it would not generate enough power when cold to power the graphics card. Once the PSU was warmed up and operating, all was good.

What I am saying is, sometimes things are not as obvious as they seem. It is rare to see a CPU go bad, although that was one of my thoughts on my first post.

I have found that the only real good way to troubleshoot is to swap parts. And I know it is not easy to do, unless you have 2 PC's.

Oh, you said that there is definitely enough power. Did you measure the voltages of the 12 and 3v rails? Did you run an amperage test? I know the answer, so dont assume anything.

In my experience, most problems as this are from the PSU. I am not saying that this is the situation for you, but really, I have changed out more PSU's than anything, and if you have bad power, it causes a lot of weird things to happen.