Problems with PC I just built

[Rob(QG)]

Hi

I just built a PC with an Aopen MK79G-1394 motherboard, Thoroughbred B XP1800+, 2x256MB Twinmos 2700 CL2, using onboard GF4 gfx.
There is also one hard drive and one DVD ROM drive attached.

The problems I have are as follows:
If the cpu is on a 133 bus it will not boot into windows xp or windows 2003 server, though it posts OK.
If the cpu is on a 100 bus it will boot into either but will BSOD or lockup at some later point in XP - seems stable in 2003 tho
The speed of the memory (266 or 333 both cas 2.5) doesn't seem to affect this.

I have tested the memory from a dos based memory test program (DocMem 2.0) at 333 cas 2.5 and it seems fine.

The issues I have seen are erratic voltages, with two different PSUs, particularly Vsb (which afaik is only important for standby), corruption and BSOD in 3d screensavers under XP and also corruption of screen with nVidia audio tuning program open under XP. The second, more powerful PSU cured the BSODs in XP, but corruption and freezing still happened.

What is the next best thing to check? As I have mentioned I have tried 2 PSUs. Could this be the processor, or is it more likely to be a fault on the motherboard?

Cheers for any help - I've spent far too much time fiddling with this and it is making me bald(er)

[Wombat]

Have you tried running the RAM one stick at a time, in different sockets?

[The PIT]

You say erractic voltages how badly are they varying???

Is this a clean windoze install??

Have tried one mem stick??

Have you tried loading the Bios defaults???

[Rob(QG)]

The main voltages seem to be not too bad. It is the Vsb that is the worst - it dips below 4V. They do seem to fly around a lot tho, but within tolerances I reckon. The voltages seem more eratic with the more powerful PSU actually The original PSU was a 200W jobbie, that I calculated to be very near its maximum, (10A on 12V) and running very hot, the new PSU isn't the best make but supplys 14A on 12V and runs cool.

I haven't tried with only one memory stick to be honest, I presumed that if it passed the memory tester that it was OK.

Probably the easiest thing to check though - will do that tomorrow evening.

Only thing is, would bad memory cause a failure if the CPU was put to the right speed, and work otherwise?

[Technoid]

1. heat (is the HS seated corectly?)
2. PSU (is it strong enough?)
3 Memory (Mem-test 86 is what I use)

[Wombat]

Originally posted by Rob(QG)
The main voltages seem to be not too bad. It is the Vsb that is the worst - it dips below 4V. They do seem to fly around a lot tho, but within tolerances I reckon. The voltages seem more eratic with the more powerful PSU actually

Your 5V line shouldn't be drooping like that, for sure. Tolerances are 10% generally on all the voltages. Something is quite wrong here. The poorer performance of a bigger PSU kind of suggests that you're getting some kind of problem from the mains. Have you tried the computer on another circuit in the house? Also, have you tried temporarily unplugging devices, like CD-ROMs and such, to lessen the demands on the power supply?

Only thing is, would bad memory cause a failure if the CPU was put to the right speed, and work otherwise?

You'd be amazed. The different CPU speeds all cause software to execute with slightly different timing, and so they are very different sequences from the RAM's perspective. But your power problems are big, and more likely the cause.

[Greebe]

ie get a real PS with ample/clean go juice

[Sethos]

your 5V line shouldn't dip below 4.5V, Idealy it would sit between 4.7 to 5 V in general...also you're using an Aopen which while not the worst, has been known (at least in my esperience) to give some head aches...

~Sethos

[Ssin]

I heard that some Motherboards with some XP+ AMD CPU's couldn't handle well. Be sure to check your HeatSink EVEN if it comes in an AMD box. They used to make HS that couldn't bring the CPU down under 40°C and that was the main cause when using DDR mem. And oh yeah.. try another motherboard whenever you can.

[Rob(QG)]

The plan is that tonight I will swap all the bits out of my other PC into this one - see at what point it starts to work properly, or if it doesn't then it's gotta be motherboard related.

I don't think it is a heatsink problem, as it runs very cool (especially as it is underclocked), and the problems remain under XP.

Not sure about the 5V line - this is just the standby voltage, rather than the real 5V line - that seems OK. But I'll try with my PSU too, that seems to be able to cope pretty well.

[The PIT]

Best way to check your voltage is slap a proper meter on it. Don't trust the Bios or software to give you the correct readings. Either your present power supply isn't man enougth or you've got a faulty connection by the sounds of it.

[Rob(QG)]

Finally getting somewhere...

The reason that Windows 2003 didn't like the processor at 266FSB, was cos I accidentally overclocked the memory to 352MHz when I set that.

Fixed that and it was stable.

Installed motherboard monitor and all looked good.


Installed XP and back to crashing - decided to fiddle with the memory. The chip that was on bank 0 seems to be the cause.

Really confused at how Windows 2003 could cope with it - possibly the bad bits were only used in the "spare" part of the gfx memory - and hence were never accessed under 2003 as it seems to have a total lack of video acceleration.

Next problem is that windows update seems to think I need no updates I've just manually grabbed SP1 and installed it - hopefully that will fix the issue. - edit - yep that fixed it

Still need to check PC at full speed, but that can wait a bit - it isn't a performance PC anyhow, it's a living room PC

Thanks for all the good advice and help - was getting mighty sick of this thing