'No Signal' on monitor. Dodgy motherboard?

antilles

Really stumped with this one. A friend's PC is showing 'No signal' on the monitor. When powering up the CPU fan is running, the hard drive makes a bit of a sound, then nothing. I've tried -

- removing / reseating memory sticks (powering on with them in and out). No difference.
- resetting the CMOS by jumper switch, and disconnecting CMOS battery. No joy.
- disconnecting all the attached devices (CD ROM, hard drive), reconnecting one by one. Nothing.
- tried the monitor and cable on another PC. Monitor is definitely OK.

There is no video card, the video is on-board. Power supply fan is running and power appears to be getting around OK, as the CD ROM will open and spin.

Any suggestions? Am I looking at a suspect motherboard here?

Edit: It's an eMachines E4252 if that's any help.

Taffybiker

Yes, I would imagine your diagnosis is correct. Often this sort of thing can be caused by a crashed or faulty BIOS chip. Try replacing that if possible, it's usually in a holder so easy enough to remove with care. It's not the only possible cause though.

HO87

Firstly, it would be useful to understand how the "No Signal" situation arose.

However, two possible causes immediately come to mind. The first - as suggested above by tb. Replacing a BIOS chip can be fiddly and not something I'd suggest a complete novice tackles as the mobo can easily be bricked.

If your friend has been changing the BIOS settings - for whatever reason - then you might want to check the on-board settings (it may have been inadvertantly switched to the wrong output depending on what monitor he is using) and if necessary try a factory settings option.

I'm pretty sure that this is the same machine my daughter had a while ago. If it is it has an ECS mATX mobo. If the pci-e slot is free then I would disable the on-board graphics and try an external card. If the external card does not work then I'd suggest that the problem is deeper rooted in the mobo.

IME on-board graphics can suffer with split joints where the vga output joins the board especially if the monitor cable is stretched slightly or is pulling down on the socket.

evilgoose

Alot of BIOS chips tend to be soldered onto the board these days, rather than been in a 'socket'. It makes changing the chip beyond the average guy.

As suggested try reseting the system, I'd suggest looking for the system battery, it'll most likely be a watch type battery (LR6 maybe), pop it out (note which way it was inserted. Leave it for a minute, then put it back in and try starting the system (make sure the power is off and it's uplugged before you do anything, also ground yourself by touching a radiator or some pipework first.

does the board have a AGP port or PCI express port, and if you know a generous person with a graphics card you could borrow, just to see if it's only the onboard graphics is dead. If it is just that, you can pick up a new card very cheaply - £25 for basic ones. It's cheaper than a new PC and you dont have the hastle of worrying about installing your software and transferring your stuff over.

Richie-from-the-Boro

- pull the memory out and re-boot - how many beeps ?
- put he memory back in & stick a graphics card in it - how many beeps
- pull the CPU out - how many beeps ?

Inactive

I had a similar problem to this, I just fitted a cheap graphics card, that sorted it.:)

Altahost

Fit a new BIOS chip???? There is NO SIGNAL therefore no power delivery. Integrated Graphics failure...simples. Inactive is correct! If you have VGA or PCI-e slot, fit a cheap Garphics card.

antilles

Thanks for all the replies, I'll try and address them all -

Problem suddenly just started without warning, they haven't changed BIOS settings, they can barely figure out how to get into Windows never mind the BIOS.

I already tried removing the memory completely. No beeps at all. Tried putting matching memory in from another PC - nothing, no beeps.

Already tried removing the battery to reset BIOS, and this has no effect. The BIOS chip is removable, however given the mobo is quite old so I'm not going to bother going down the messy route of getting another chip.

The mobo does have PCI slots, I will see if I can get a graphics card and try this, as suggested it may be onboard graphics that have failed.

CHR15

I agree a separate graphics card is the most sensible approach, but just to take a step back and clear all the simple things.....

Does the monitor have a Digital/Analogue switch??
Was the other computer connected the same way (DVI/VGA)

This could be a case of the monitor being swtiched to the DVI port instead of VGA (or vice versa) so sees nothing.

Just thinking out loud.

Taffybiker

I would be interested to learn the outcome of this one. I have been asked to fix several machines with this kind of symptom, and each time I have tried another graphics card without any luck, though I am glad to hear it has worked for some people. On one occasion a new BIOS fixed it, another was a faulty PSU, but the others have all needed a new mobo.

rygon

I had this problem last week and was using a seperate graphics card. Fans would run but wouldnt slow down as usual. Took everything out of the slots and no beeps. Bought a new motherboard from ebuyer for £50 (takes AMD am2 / am3 processors) and that solved the problem.
If you can get a graphics card for free to try then ok, but seeing that motherboards are so cheap nowadays it may be worth spending the money on that