How to diagnose PC problem

cracker

Hi

I have a home built PC which has been fine for a couple of years but is now giving me grief. I suspect the motherboard but I am not sure how to be certain. When I power up the main fan, cpu fan and hard disk (I think) start up but I get nothing on the monitor (no signal). I don't even get the option to enter setup. I have tested the graphics card on a PC in work and it is fine.
So, is there anyway to confirm that it is the motherboard. If it is the motherboard is there anything I can do other than just replace it?

Thanks

D.

matt-dublin

pull out all the ram and see doed it boot.

sounds like a faulty ram chip.

is there any flashing lights on the front?

Also mage sure the display adaptor is seated properly.

cracker

Thanks for the suggestion but not luck with that. I tried booting with both RAM sticks removed and also with each one individually and no luck. The graphics card is definitely seated OK. Is there anything else I can try? Even if it is gone I would like to find out what is wrong in case there is something wrong with my setup. I don't want to buy another one and have the same thing happen.

If I have to get a new motherboard I was going to do a proper upgrade. I was thinking of this one http://www.komplett.ie/k/ki.aspx?sku=321774

It is a bit overkill for my pentium 4 and ddr2 pc2-4300 ram but I can upgrade them in a couple of months. Does anyone have any experience with this or simialar boards?

Thanks

D.

zilog_jones

Try taking out everything else that isn't necessary. With even just the CPU in it should at least make some beeps or something (not sure if they all do though). Are there any diagnostic lights on the motherboard? Could be the power supply that's at fault as well.

You mention your P4 is a couple of years old - you sure it's socket 775 like that new motherboard and not the old 478?

cracker

It is definitely a sockett 775, it is a foxconn 925xe and it has all been working fine for a couple of years. I just powered it down the other night and when I went to start up again no joy. I did switch off the power switch on the plug strip which I don't usually do.
I can hear the main fan, cpu fan, hard disk and dvd drive all starting up so I thought that this meant the psu was OK but I guess it could be the particular connector I have attached to the board, I will try switching them tonight.
I can't see any lights on the board and there are no beep errors when I start up.

eurjen

Hi

I had a similar problem about 1yr ago and the end result was to replace the either the pc or the motherboard.
The fan you are hearing might just be the fan on the power supply and not the cpu fan.
As part of the boot up process you sometimes get a beep when the pc has completed the Bios. Do you hear that beep. check your motherboard manual for the correct key to enter Bios Setup. and try to enter the bios setup by pressing this key when you power up.

Your Bios is located on the mainboard and if you cannot enter the Bios this usually indicates that your motherboard is very sick. If you can enter the Bios then the problem is probably to do with your operating system.

I am assuming you have tested the monitor and that is ok?

hope this helps


Jen

zilog_jones

cracker wrote:

I did switch off the power switch on the plug strip which I don't usually do.

That could suggest dodgy cap's either in the motherboard or the PSU. When you "shut down" a PC it doesn't really turn off - there's still power going through to the motherboard as the power button and some other stuff are controlled by the motherboard. So while it's plugged in (unless there's a power switch on the PSU) it's still on, and some cap's will stay charged.

I can hear the main fan, cpu fan, hard disk and dvd drive all starting up so I thought that this meant the psu was OK

The board could be dead, or there could just be not enough (or no) power getting to the motherboard, CPU, RAM, graphics card or whatever else that you can't see/hear turning on.

but I guess it could be the particular connector I have attached to the board, I will try switching them tonight.

There's usually only one main motherboard connector (the 24-pin one or whatever) coming from a power supply - that would be the most important one. Try a different PSU if you can get hold of one.

cracker

I tested the monitor with a laptop and it is fine. I don't think that it is a power problem because I can hear everything start up, hard drive, cpu fan, dvd drive. I only have 1 hard drive and a pci express graphics card other than the standard stuff and the psu is a 400w so there should be plenty of power. as you said Zilig there is only one motherboard connector. But this must be OK because I can see and hear the fan on the north bridge start up and this fan is connected directly to the motherboard so there must be power getting to the motherboard

Auvers

Have you cleared the CMOS using the jumper or pulling out the battery?

Peanut

Did you try re-seating the CPU?

It may have come loose, or the heat dissipation has degraded so much that the CPU is overheating on startup.

I had a similar problem with no diagnostic beeps etc. happening, removal of CPU and re-application of thermal paste did the trick.

cracker

I did try clearing the CMOS using the jumper but not by removing the battery. I will try that tonight.
If that dosn't work I will try the to re-seat the CPU. Where would I get thermal paste from, would maplins or pc world do that?

Peanut

Yeah Maplin will certainly have it, not so sure about PC world.

zilog_jones

cracker wrote:

...But this must be OK because I can see and hear the fan on the north bridge start up and this fan is connected directly to the motherboard so there must be power getting to the motherboard

All that's telling you is there's power going to the northbridge fan. It could still mean there's power say not going to your graphics card or something else. The fan probably runs off the 12V rail - a lot of other things don't. It's probably more likely the mobo is borked (assuming everything else is OK), but there still is the chance it's the PSU.