There was a problem awhile back with defective capacitors coming from a supplier which affected many of the major mobo manufacturers. If your mobo is more than a year old check with your mobo manufacturer to make sure yours isn't one with the bad caps. You could also have a bad PSU as was stated.
Dirt on the caps could just be from the cooling fan. Since most motherboards have several caps in close proximity to the processor, it's normal to find some dirt on them. As long as you clean regularly, it won't build up enough to be a problem, and dirt alone isn't an indicator of a failing cap.

Thanks Barry:

That option was disabled - has not been of help as the system just freezes and I have to physically reboot (reset). Wish as I may, I am unable to run the CHKDSK option as the unit freezes before I get to the recovery console and I am unable to boot into the system through a CD or floppy. Am hoping that some hardware change will get me to the recovery console OR boot thru CD...till then I have no options but live with my frustrations.

Regards

Thanks Charles - let me check with my mobo mfr - this unit is over a year old - circa Jan/ Feb 2004...maybe its the bad capacitor lot. Again, as you rightly point out the dirt was on small capacitors just over the processor/ fan...so I guess I can write them off as dirt. Hope I get some leads from my mobo maker...will keep you updated. Rgds.

Ananth, as Charles pointed out, dust is not a problem. If you can blow a "puff" of air on the cap and dislodge the dirt, you haven't found leaking electrolyte, that's just normal house dust. Leaking electrolyte will either leave an oily or gluey residue or a crusty deposit that's pretty well stuck to the capacitor (mine looked like lumps of dried mud!).

And yes, you could very well be suffering from PSU issues. Power quality from a PSU can vary depending on temperature and load, so if you have a marginal PSU it may perform fairly well when warm but poorly when cold. (My DVD player that failed showed the same "needs to warm up" behavior before it completely died, and its bad caps were in the power supply.) There are a huge number of very low-quality PSUs in the world because they're not a very "sexy" part of the computer and often get overlooked, but if the CPU is the brain of your comptuer, the PSU is its heart, and a malfunction there can kill your computer dead.

If you have access to another computer that you can disassemble, swapping a power supply is not too hard. There are four screws that hold the PSU to the case, and then some (fairly) standard plugs that connect to the mobo, disk drives, etc. Aside from the hassle of dealing with an unweildy bundle of wires, it's pretty straightforward.

Just make sure the "good" PSU you swap in to test is big enough. Late-model computers like yours consume a lot of power. As a guess, you probably wouldn't want to use anything less than a 350W supply, and 400W or higher would be better. (The quality of those watts is at least as important as the quantity, though. If you end up buying a new PSU, do a little research via Google and get a good one.)

Jim

Thanks once again Jim. Have already written to my mobo manufacturers and awaiting further directions from their side (they acknowledged my email pretty fast though). I do not have a spare PC (just a laptop), so access to another PSU is ruled out unless I buy one. Any other thoughts on how I can confirm or eliminate PSU as a problematic unit? If not, let me try and rule out the mobo before moving to the PSU.

This leads me to wonder on my current problem with mup.sys. Can a faulty mobo or PSU prevent booting up using a CD or floppy? or not let me access the repair console in XP either? As in, I could be stuck with two issues here - one is a hardware fault causing a system freeze and then I get onto the mup.sys/ agp440.sys issue? or maybe both are related....Rgds

Hard to say. I won't say for sure that you don't have two problems, but I think it'd be a pretty big coincidence for both issues to manifest themselves about the same time. As for system behavior, I am not at all qualified to explain how the loss of any given capacitor(s) in the PSU or mobo would manifest themselves as problems. About the best I can offer is that such problems generally make the system "unstable" at best, and plain ol' dead at worst.

It seems possible at least that all the effects you see could be tied to a single hardware problem, but I can't say that's the case for sure. I wish I could offer you something more definitive.

Jim

After sufficient warm-up, I manage to get to the windows boot up stage where I am presented with options on Safe mode w/ w/o networking, Normal etc...and the unit goes onto freeze at mup.sys. In Normal mode, it freezes almost immediately (with the time countdown frozen as well).
Well, let me take one step at a time maybe the hardware resolution could provide a clue to the mup,sys issue. A predominant number of mup.sys/ agp440.sys problems seemed related to use of SATA HDD in a XP SP2 or W2k SP4 environ...makes me wonder...

Guys, would downgrading to WIN98 SE resolve this problem? I pretty much tried everything on my wife's computer and it worked but the following day it just went straight to the BLACK SCREEN OF DEATH with the little cursor on the top left. It took her 7 restarts to get something up again.

You didn't post enough info for me to even guess, but I will say this: In general, if you have a problem that is inconsistent (i.e., the boot hangs seven times in a row, but on the 8th attempt it works), the problem is usually hardware-related. (In general, the OS software always runs the same way every time you boot, but the hardware might respond differently from one boot attempt to the next if it's malfunctioning.)

Jim

Yeah I guess Daniel never got to MUP.SYS or AGP440.SYS.

So many different solutions...

Our was bad capacitors. This system (GigaByte PIII w/VIA chipsets) had been working fine. Yesterday, it started to reboot at "mup.sys" and would go into the reboot loop. If we left it off for awhile, it would boot into XP but would reboot after just "sitting" in XP. I haven't read all the posts. I wonder how many have been bad capacitors.

Jeff;

If they haven't compromised their enclosures (by the way the little letter-like scoring on the electrolytic capacitors is to keep them for exploding), it's hard telling. Due to the (up to)six-layer boards manufactured these days, replacing them usually causes more damage.

Re: "...replacing [capacitors] usually causes more damage." I don't have enough data to say with confidence what "usually" happens.

I am a complete duffer when it comes to soldering, only undertaking such jobs once every three or four years. Even so, a couple of months ago I sat down and replaced all the bad caps in my two mobos and DVD player. Took me about 30 minutes to replace 5 capacitors (a handier person could have done it in 10), and all three devices are currently up and running.

The way I see it, if the device is broke anyway, and you have a soldering iron lying around and aren't afraid to use it, it seems like there's little reason not to try. I spent ~$15 on replacement caps and salvaged ~$250 of equipment.

Your mileage may vary.

True. Radio Shack is running low on components these days. Digikey is a good source though.

Sorry guys for not posting more info. I did get to the MUP.SYS or AGP440.SYS issue. I tried the "Chkdsk /p as suggested and the other command that ends with /r. That worked and then I went back the following day it was the same issue.

I ended up reformatting to FAT32 to see if that would help. And it did but then as I posted, the following day she had got the BLACK SCREEN OF DEATH with the little cursor on the top left.
The system hangs at startup and lags big time when the XP bar is displayed during load up.

Am I dealing with hardware failure as suggested or is this that blasted software bug MUP.SYS or AGP440.SYS????

Daniel, Your predicament seems same as mine - could not boot in, deleted and changed partition to FAT32 and managed to boot into safe mode once or twice and then back to mup.sys or agp440.sys. In my case, it has been a steady decline since and I am convinced with the hardware failure theory. I could not spot any bad capacitors or electrolyte oozing or bulging caps, but the symptoms for capacitor failure seem to tally. All the best with your troubleshooting...will keep watching this column for how it goes...

After reading Ananth's and Daniel's posts, I'm wondering if formatting and completely re-loading Windows would have any results. Daniel, if you can do that, 98SE would almost certainly work fine. The mup.sys/agp.44 issue seems to only affect Windows XP SP2 and 2K Pro SP4 as far as I can find. 98SE is built on a different kernel, or platform, than either of the newer OS, which are built on NT. Simply changing your file system to FAT32 while leaving the XP install intact doesn't really change anything, the drivers still load in the same order and as far as I know, any hardware issues won't care one whit which file system you have if you leave the OS installation intact. Personally, if I couldn't fix the problem within a reasonable number of attempts, I would try formatting and reloading Windows XP. Making a hardware change was what caused my Win2K system to hang, but luckily I was able to fix it without too much drama. If you have data you cannot afford to loose via a format, then you have your work cut out for you getting things running again. I keep all my data/files I don't want to loose on a separate partition from Windows, so if a format is needed I don't loose anything. If you can, try formatting your c: drive (or whichever drive/partition Windows is installed on) and do a fresh install of Windows. If you don't already have your drive partitioned into at least 2 virtual drives, I would highly recommend doing so. Make your Windows partition around 10 gigs, then partition the remaining space as you see fit. Keep all your important files on a different partition. If you don't know how to do this, a Google search can help. Norton's Partition Magic is a very good tool to create/manage partitions.
XP also has some partitioning ability built in.
I sure hope something breaks soon with all this, I know how frustrating it can be when your computer won't behave as it should and you can't find a solution. Been there done that.

Thanks so much for this great info guys. Well, I guess it's time to zero in on the hardware failure. What are some of the things I should look at first?

I fell victim this morning.

I awoke to an error message saying that my computer had a problem writing to my 300GB Maxtor HD (#2) which I use for storage and backup - it is partitioned into 2 drives (F and G) and is ATA.

So I figured I would restart and see what would happen - and windows just hung on the welcome screen for about 10 minutes or so at which point I did a hard restart and tried safe mode - walla mup.sys!

So I let it run for a while - then tried again - same issue, except this time I let it run while I read thru this forum. Whaddya know, after a while the welcome screen came up, I clicked my icon and waited....about 10 minutes, then the desktop showed up, then I waited for about 10 minutes... you get the picture. So I did a system restore - all of which took about an hour! Restarted and you guessed it - just hung again forever.

So know my battery is in the fridge - I figured that was the easiest first step. Then I suppose I will try the restore from the XP disk, then the file check stuff. I guess I will let you know how it goes. What a pain in the arse!

Thanks for all the useful info - if anyone has any info that seems would help my specific situation would be great - I don't want to have to take this thing to a "professional" (no offence to any here, I just hate spending money on stuff like that - I'd rather buy a new HD!)

Since you had error indications with the hard drive before your boot problems started, I'd focus efforts there first. Have you tried swapping IDE cables?