New Athlon XP motherboard?

[Harrison]

I've just had a PC in to repair from a client and on fully testing it I'm now sure the motherboard is faulty.

On switch on the system and CPU fans spin and you can hear the HD spinning up but the system doesn't beep or go to POST. Because it doesn't even beep or go to post it can't be the ram, cpu or any other components because it doesn't even reach the point where it tests for them. Therefore it can really only be the PSU, motherboard, or corrupt CMOS memory.

Clearing the CMOS memory didn't help, and testing the system with another working PSU gave exactly the same behaviour as the system's own PSU.. I also tested the PSU voltages and they all seemed fine on all rails of the PSU.

Also looking closely at the motherboard a couple of the capacitors look like they are leaking slightly out of the top which is never a good sign.

I spoke to the owner and told them the options. Source a replacement identical motherboard, a motherboard compatible with the existing CPU and ram, or get a new motherboard and CPU.

As the existing motherboard is no longer made I would have to find one on ebay. There is one but it has 4 days to go and already has 4 bids from different buyers so there is interest, so no guarantee I would win and it's already up to £20 which is expensive for quite an old second hand Athlon XP mobo.

Next for a new compatible motherboard, which is really the best option if I can get one. So does anyone know anywhere still selling new Athlon XP motherboards?

One other thing. With a Micro ATX motherboard fit in an ATX case? (same stand-off locations?) I've never tried fitting a Micro ATX mobo in an ATX case. Reason I ask is because I have found on ASRock Athlon XP motherboard that would be perfect but it is a Micro ATX size.

I basically need an Athlon XP compatible motherboard that can use DDR 333MHz ram and is priced under £40.

Failing that he has given be the go ahead to junk the current setup and stick a new motherboard/cpu in the system for around £60 which is possible, but I would need to use the existing ram to keep the costs down and that could be an issue with newer motherboards.

[Bloodwych]

Definitely seems like the motherboard.

Sounds like you've ruled out many causes. The leaky caps were a common issue of that era of boards and if they do look bad the motherboard needs replacing regardless as it's just a matter of time before they fail, even if it's not the current issue.

I know it sounds silly, but some motherboards won't post if the CMOS battery is dead. Most will and just won't save the settings and lose time, so I doubt it's that but I just thought I'd bring it up.

mATX boards fit ATX standoffs fine - they just don't use the bottom set.

Can't think of where you'd get new Socket A boards from. Some manufacturers do refurbished units, but it would probably be cheaper grabbing something off ebay as you've mentioned.

Had a quick look on ebay:

http://cgi.ebay.co.uk/ws/eBayISAPI.d...m=250170205979

New and 100% tested. DDR 333 will work fine at 266. Need to check manufacturers website for CPU compatibility if it's a fast Athlon XP.

Some second hand ones ending soon:

http://computers.search-desc.ebay.co...refinesearchZ1

[Harrison]

Thanks for the links.

Sadly the KT266A chipset is for the older 266MHz FSB Athlon XPs such as the Palomino versions, and I need a chipset that supports a 333MHz FSB for newer Barton CPUs.

I've now found a new Athlon XP motherboard. ASRock K7S41GX for £27 which is a Micro ATX motherboard and should be OK for what the owner needs.

[Bloodwych]

Hope everything goes well.

I thought the CPU might be incompatible, as mentioned above. Well, it would work, but I don't think the client would be happy with a slower machine!

[Harrison]

Exactly.

I've now ordered it so hopefully it will arrive tomorrow and miss the 5 day postal strike!

[Harrison]

[begin rant]

Don't system builders know what the purpose of thermal grease is?

Every pre-built system I've repaired or upgraded for people have had extremely excessive amounts of the stuff gunging up the CPU and heatsink!

All that should be there is a very thin (1mm) thick layer of thermal grease between the CPU and heatsink to fill in any undulations in the surface of both the CPU and heatsink plate, making a smooth surface to maintain contact with the most surface area between the two for maximum heat dissipation. Any more grease than that at it has a reverse effect and makes the heat dissipation less efficient.

[/end rant]

Deep breath...

Some may remember I had trouble removing a Pentium 4 from a socket a while back, while repairing a system for someone. The heatsink would not come away from the CPU even though it was unlocked from the motherboard. A hair dryer on its hottest setting eventually freed them and the amount of thermal grease on the CPU was silly.

And today, while waiting for a motherboard to arrive, I decided to strip down the system ready for the board. One removing the heatsink I have discovered that there was so much thermal grease used that as it had got hot it has spread out from just being over the CPU and has also gone all over the surrounding circuit board and circuits. That's one downfall of the older Athlon chips as they didn't have a heat spreader over the CPU and the actual CPU is exposed making it harder to clean.

[Bloodwych]

I agree, they love using that cheap white crap that spreads everywhere and because it isn't conductive they just lash it on.

The wax that comes pre-applied to heatsinks is also a pain to clean off. I always remove that rubbish and apply as you said - a nice thin layer of compound, preferably artic silver which is well worth the money as it lasts forever and it's easy to clean.

The first time I came across the stuck CPU scenario convinced me to always run a benchmark program and get the CPU nice and hot before removal. Never had an issue since.

[Harrison]

That's OK if the system is working, but normally I get them to repair when they are dead (PSU or motherboard normally) so I can't warm them up first.

One good tip to always remember after warming up a CPU is to not just grab the heatsink. They can be bloody hot!

[Bloodwych]

LOL! Great health warning there! Those things do get toasty.

I've been really lucky with computer hardware - not one failure. I'll be sure to have a hair dryer handy when I do however, although I don't think arctic silver has the issue.

[Harrison]

If the compound is applied correctly you shouldn't ever have such issues. Its only when some smart arse has caked the CPU in the cheap grease and the stuff sets like concrete when it goes cold. Good quality thermal grease will stay greasy even when cold.

You are really lucky if you have never had a hardware failure. I've had a few over the years. Over the years I've had a PSU blow which has taken the motherboard with it, a motherboard go wrong causing bad system instability and a video edit workstation go bang taking the PSU, motherboard, one of the two CPUs and a couple of the HDs with it.