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View Full Version : Computer does not POST, no beeps - nothing!



kiki
01-06-2004, 05:21 PM
Yesterday I was putting in a new hard drive and everything was working well. Then last night I left my computer on and in the morning when I turned the screen on it was saying 'No input check signal cable'. So then I tried turning the monitor off and on again. That didn't work so I tried turning the computer off and on again. Now it doesn't even turn on! The PSU powers up and the CPU and video card fans spin away but no POST, no beeps, nothing. The hard drives, floppy, cd drives do not power up or anything as far as I can tell.

All that I can determine is its powering up some things but not other things. The fact that it can't POST is worrying enough. I have no idea what the hecks wrong with it :|

So far I've tried resetting the cmos (didn't work) and also tried putting a brand new cmos battery in. No change whatsoever.

Tried checking all the cables, and connectors to make sure they are seated properly, still no go.

Tried 2 different video cards in it, nope.

Tried 2 different CPUs in it (one known to be working), still nothing. Not even a beep or something.

I've since taken everything out of the system and left the CPU and RAM in. Still doesn't do anything.

Tried CPU only, no beeps or anything. Motherboard speaker is hooked up too by the way.

I'm thinking the motherboard is stuffed??? That would mean a new motherboard and RAM as this ones so old its unreplaceable :( Got a CPU that should work ok in it.

Anyone got any ideas? Help? :(

Specs:
KT133A - 7AIA5 MB - 280Mhz FSB Motherboard
XP 2400+ T-bred core
384mb PC133 SD RAM
Ati Radeon 9800 pro 128Mb DDR 2.8ns
160Gb WD 8mb cache
120Gb 7200.7 8mb cache
Enermax 350W PSU.

Billy T
01-06-2004, 05:46 PM
It could be the loss of a PSU rail kiki, fans etc would still run but there might be no juice to the CPU or the MB etc. I have just dealt with a similar problem where the 5 volt standby volts were low and nothing worked apart from the fans etc.

Can you swap in another PSU? It's worth a try.

Cheers

Billy 8-{)

falvrez
01-06-2004, 05:49 PM
Could still be your RAM _ had many cases were no motherboard beeps to indicate it but RAM dead. I did read yor message properly (I hope!) and didn't see that you tried some other RAM. I guess not all of us has spare RAM lying around tho...

Tobas
01-06-2004, 06:00 PM
Suggest you take out all ram and replace each stick one at a time as you may have a faulty stick, but more than that, make really sure that each stick inserted is fully seated and locked into place.

Growly
01-06-2004, 06:11 PM
It's interesting that I had the exact same problem at the beginning of the year with a friend's computer... have a look for what i posted, it should have have a title along the same lines as yours.

In the end it turned out that his CPU was dead. Some motherboards, i subsequently found out, will not do ANYTHING unless they have a workign CPU attached. Other motherboards, will POST but will return a set of errors that tell you the CPU is broken.

Is it under warranty?

kiki
01-06-2004, 06:11 PM
> It could be the loss of a PSU rail kiki, fans etc would still run but there might be no juice to the CPU or the MB etc.

Whats a PSU rail?

I'll test the PSU on my spare system, see if it runs ok. The enermax is only about 3-4months old and no idea why it would crap out all of a sudden, but things happen :O

> I did read yor message properly (I hope!) and didn't see that you tried some other RAM. I guess not all of us has spare RAM lying around tho...

> Suggest you take out all ram and replace each stick one at a time as you may have a faulty stick, but more than that, make really sure that each stick inserted is fully seated and locked into place.

I've taken them out completely. Would the computer still POST without ram?

I don't have spare ram lying round, just the 128mb and 256mb of PC133 sd-ram.

I'm going to be trying most of the components out one at a time on the spare computer beast, to see if they are still alive.

godfather
01-06-2004, 06:31 PM
A PSU "Rail" is a voltage line (Voltage Rail)
Such as +12v, or +5v etc.

What is suggested is that the operation of fans may just indicate that the +12v rail (or line) has a voltage on it.
It may be incorrect (but the fans would not care) or the + 5v may be dead etc..

kiki
02-06-2004, 04:21 AM
Well after 3 hours of arduous testing and swapping one thing in and out at a time into the spare working computer, I've confirmed that:

The power supply runs fine.
The 2400+ and 1.1Ghz Athlon CPUs run fine, no problems.
The 9800 pro video card runs fine as well.
The hard drives are running fine.

The only thing I haven't tested is the memory as I have no way to test it. I'd need a known working board that takes PC133 ram. I'm guessing it probably works ok anyway, but I'll ask a friend to test it for me.

That only leaves the motherboard left right?

Well in a way I'm kind of relieved, means I can justify an upgrade, but on the other hand its a lot of money :(

What could have caused the motherboard to just die like that???

Also some suggestions for a new, cheap Socket A motherboard and some RAM would be awesome. :) I'm thinking definitely dual channel DDR and low CAS latency <= 2.5. I'll probably be overclocking so the ram probably needs to be 333Mhz or 400Mhz to give plenty of room. 512mb minimum .

Also I'll need a new case, this other one is just too small and is a major hassle trying to fit stuff in. Black?

Keep it all in the range of $500~

TIA!

godfather
02-06-2004, 08:25 AM
> The power supply runs fine.

Are you saying that you have verified with a voltmeter that all "rails" are within specified volages?

kiki
02-06-2004, 09:54 AM
> Are you saying that you have verified with a voltmeter that all "rails" are within specified volages?

:O No, I just plugged the PSU into another computer and connected all the components up. Looked like it ran fine to me. Do I really need to get a voltmeter out?

Billy T
02-06-2004, 10:08 AM
It could be worth checking with a meter kiki, unless of course you really do want the justification to upgrade.:D

The difference between boot and no boot on my faulty PSU was around 0.25 volts on the 5 volt standby rail.

It was down to 3.46 volts but would still start OK at that level. It varied intermittently as well, and if it dropped to 3.2 volts it wouldn't start up.
Fitting an external cap raised the output to 3.8 volts which is still 1.2v below the spec but enough to make it start every time.

Incidentally, it had been making an annoyingly loud sizzling noise from the PSU when switched off, which my son complained about because the box is less than a metre from the head of his bed. Fitting the cap stopped the noise which was an added bonus.

Cheers

Billy 8-{)