Hit by a surge?

[jabberwok]

:confused:
Anyone come across this before?

Computer froze (not mine thank heaven) and "wouldn't work". Normal sort of call that can be traced quite quickly - not so this time.

Switched it on, splash screen came up and - it rebooted! Kept doing this so I went through the step by step option. Autoexec.bat was accepted but config.sys would fail at some stage (never the same point). Very odd.

Booted from floppy and got command prompt. Ran Scandisk but it locked again. DIR on both drives showed structure intact and TYPE would list TXT files. I could even run a DOS game OK - but many progs (OK those that I could get to work in DOS) would lock. Corrupt HD? Yes, I did find evidence - but it gets stranger.

Got the WIN98 CD and Start up floppy. Setup locked. Next ran FDISK and wiped the drive, then formatted it (drastic now). Windows setup still locks - as does Scandisk from the CD. Loads of other tests using both hard drives and then each individually. Result always the same - can get to DOS, list files and open some - but the computer just refuses to go any further.

At one point when I tried running Scandisk it started to print out directory lists and once it came up with "Program caused a Divide Overflow Error"!!

So what is it I haven't spotted? I think one HD is kaput and the other suspect but I am wondering what may have caused this. Also, could further components be damaged that might result in this odd behaviour?

I'll add that I've checked all floppies that I've used during these tests and they appear virus free - and reformatted one HD - but no luck there.

Any suggestions welcome!

[What_does_this_button_do?]

If you live in London around the WC1 area and this was Friday I can confirm a power spike did occur - we have lost 50 PC's and I've got two teams in at the moment swapping kit out.

The fault you describe ties up with a surge.

[ICU]

Problems like this occur when the RAM is faulty. Do you have any spare to try? If it was a surge issue, I wish you luck.

ICU

[fobotcso]

I'm almost afraid to chip in with this; it does sound kind of terminal.

You don't say you did it so I'll ask the question; have you switched off and removed all power for 5 mins and done a cold reboot?

Probably have; probably so obvious you've done it. Sorry I mentioned it...

[jabberwok]

Yep, did many cold reboots and quite a lot more but I was trying to keep the message short!

I've now removed both HD's and RAM and still no luck. I can still boot from floppy, put files on the HD and list these with DIR or TYPE. Trying to run any EXE file almost always results in a lockup - they never finish.

I'm still puzzled as to why I can use DIR, MEM, TYPE, CHKDSK and a load of other commands quite happily but the thing falls over whenever I try to run most programs. It does not seem logical to me that (for example) a DOS game can run, which means the systems are working, but Windows setup caused a lock. The only factor I can think of right now is file size and that it doesn't like big ones - but I'll admit I am looking for any sort of clue here as I can't understand the nature of the problem.

I still get an occasional "Program caused a Divide Overflow Error" but is this valid for a file like Scandisk?

With memory and HD both replaced that only leaves the mobo to check but can anything on it cause such weird problems? The BIOS appears to be working OK as I've reset HD values several times when swapping these around.

As you can guess I am really puzzled...

[Cornish Jack]

Sounds unfortunately similar to a problem I had. The cause? - the processor had, somehow, been overcooked. Might have been a spike but nothing else was affected.

[SLF 999]

From experience if the HD is cooked or corrupted beyond saving (as yours seems to have been) I would certainly suspect that the processor is also cooked and the memory is the same.
Perhaps someone will correct me but dont DOS programs, commands run in low (or is it High) memory, and is it possible that the memory is ok to let DOS run but windows using all memory is failing?
Maybe this is rubbish but just a thought that went through my head.

[What_does_this_button_do?]

If you boot from a Win 98 CD and it loads the setup program then the processor and memory is OK....

[Brit Abroad]

I have heard of these kind of problems when there are certain USB devices connected to a PC with a VIA chipset on the motherboard.

Might be worth disconnecting all USB devices and trying to boot.

Good luck and keep us informed.

[ICU]

Another thing to try (if you haven't already) is run Windows in SAFE mode. I can't see your problem being driver related, but see what happens in SAFE.

Do the failing programs work in this mode?

Let us know

[fobotcso]

If you really are booting from a raw DOS floppy with no Config.sys or Autoexec.bat, then the problem can only be MoBo. Raw DOS loads in conventional memory unless you specify extended Memory (< 1MB) with HIMEM.SYS, EMM386.EXE and UMB etc.

Of course, DOS won't reconise long file names or NTFS/FAT32 file structures etc. Furthermore, loading a display driver that wants to run in high memory, but you haven't specified it in Config.Sys, will lead to difficulties.

Perhaps you try the old trick of pressing F5 when the text "starting MS-DOS..." appears during a DOS boot to by-pass the config.sys and Autoexec.bat files.

Again, sorry if this is Granny/Eggs territory, and it may not all be strictly accurate anyway, but we're all getting desperate out here!

[jabberwok]

Sorry to repeat some things but the suggestions are drifting off target :)

1. I'm stuck with DOS. Windows setup (from the floppy) locks the machine.

2. Hard drives have been wiped with FDISK and reformatted (showing that FDISK and FORMAT both work). I have now tested both HD's on another computer and there's nowt wrong with them - surface scan with Scandisk reports no bad sectors. Whatever caused them to get corrupted was elsewhere.

3. Memory has been replaced but the problem persists. The glitch must therefore be in the mobo or CPU. I haven't yet tested the memory I took out to see if it's OK but I'm guessing it may be useable.

4. It's a pre USB mobo - Asus P55T2P4 so USB isn't really an issue. Apart from that I've got the thing in pieces here with no devices attached apart from a floppy, one HD and a CD.

5. The CPU isn't overclocked - it's a P200MMX and that's about the max level of the mobo. (On the other hand the machine I'm using here is a P650 overclocked to 850)

So it's now narrowing down. The "event" that caused the problem may have been a spike but it could be a mobo/CPU partial failure. Whatever happened it corrupted the HD's and it still doesn't allow me to go beyond running a few DOS commands.

I'm just about to try disabling the L2 cache as this is an expansion slot on the mobo.

[ICU]

Clutching at straws now...... :confused: It might be just the floppy at fault, or maybe the CDrom. Might be ok for DOS but won't run windows setup files.....

well I did say clutching at straws.... (but you never know) ;)

Keep us posted. This is getting interesting.

[Brit Abroad]

Maybe a virus ?

Sorry can't think of anything else.

Has this computer ever worked with what you're trying to do ?

[jabberwok]

Cracked it!

Disabled the L2 external cache in the BIOS and it worked.

On the P55 mobo you have a Level 2 external cache. This can be onboard chips or a cache expansion slot - the latter taking a Coast cache module. It looks like the surge has knocked the module out.

I've now reinstalled most of the basic software and I've had no problems but I'm not happy with keeping the mobo in case other components have been weakened. Once I get the HD data verified I'll replace the motherboard.

I've now checked the original memory and all four SIMMS are working fine - as are both original HD's. The only casualty in this event is the L2 cache (and the corrupted data on the disks).

Thanks for everyone who chipped in with suggestions - it did help clear my mind of inessentials..