Narrowing down the search for possibly damaged hardware

[Seeker47]

A few weeks back, I had a PSU go up in smoke. Literally. I have some reasons to think that it took some other components along with it, though troubleshooting this has been less than clear. See if these symptoms -- after the dead PSU was replaced with a new one -- suggest anything to you.

When trying to boot XP, the initial drivers-loading screen comes up but does not get very far, as the computer reboots before it gets beyond that point. However, when I swap those HDDs into a working twin of this computer, they function normally. In fact, I have been using them extensively ever since. So (fortunately), I'm confident that those HDDs that were in the computer when the PSU went "poof" did not get trashed.

If I try to boot various Linux Live CDs or repair CDs / DVDs on the PSU-replaced computer, which used to boot fine there with no problems, they now just go off to La-La-Land, halting on a blank, black screen.
However, I can still boot up the DFSEE bootable CD, which is FreeDOS-based and text mode, except for a few graphs. This tells me two things: 1) The optical drive is still o.k., & 2) The video card in this rig is likely still o.k. Make that three things: I think it shows the replacement PSU is working as it should.

That would then seem to point to three remaining suspects: the RAM, the CPU, or something on the MB. I'm aware of some RAM-testing programs, which I think take a rather long time to run. What sort of diagnostics might I use to check out the latter two ? (Swapping those components out -- in classical troubleshooting fashion -- would either be a gigantic PITA, or just not possible. I'm not going to mess with the working twin computer, since that has become my production machine, and I don't presently have another spare of that MB anyway. Changing out that CPU might be possible, but quite a bit of trouble. I'm just wondering if there might be another reliable way of testing to determine what failed ?)

[prouton]

RAM tests like MEM86 don't necessarily take a long time to run. For the kind of errors you're seeing, I think you'll know within 10 minutes or so. And yes, it does sound like the RAM could easily be the culprit.

[redwudz]

It's not likely the CPU or it wouldn't run at all. I would suspect the RAM, but you didn't mention if you got any BIOS beeps or if they were normal. If you have two sticks of RAM, pull one and try to run the PC. Then trade in the other one. But a RAM test like Memtest86 can take as long as you want it to run. Sometimes the fault shows up in a few minutes. http://www.memtest86.com/ Just let it run overnight if needed.

I would also unplug all drives except the boot and all cards except the video card to eliminate other possibilities. A damaged floppy or optical drive is a possible cause.

If it's the motherboard, at least your CPU and RAM and other parts may be OK. No simple way to test a MB. You could pull the BIOS battery for a few minutes with the PC unplugged and reset the BIOS, in case that got scrambled, but not much else to do before MB replacement.

[AlanHK]

There is usually an option in the BIOS for an "extended" test on booting, default is often to skip that.
Set it to test and see what it tells you.

Also it's very simple to make out or replace RAM. It won't boot unless you have at least one RAM chip in, but you can take out all but one and see what happens, swap it with another one if it still fails.

[Bjs]

Its usual for troubleshooting issues to include the motherboard make and model ... some things are very specific.

Booting from multiple bootable discs ... and success with one which seems to be built around freedos ... I suspect when the other os's have tried to load power manager drivers the system has halted or rebooted ... sounds like the apic chipset which controls power management is out of order ... if it were dead you wouldn't even get the post signal.

[Nelson37]

So attempting to load two different, GRAPHICAL operating systems fail BEFORE the GRAPHICAL part loads, while a NON_GRAPHICAL operating system does load, and you are eliminating the video card (that would be the GRAPHICS card) from being a possible problem?

At least your failure is consistent, and not one out of 5. THOSE are a PITA to deal with.

Swap the RAM from the good system, do the same boot test. An absolute and certain answer will be had within 5 minutes, checked both ways as you can also test the sustpect RAM in the good system. Ask yourself the question "How am I determining that a problem exists in the first place?" Next question is "What test will tell me that the problem no longer exists?" The answer is Seeing that the problem No Longer Occurs. The swap, AND the test, will take less time than installing and starting a memory tester, much less the running time.

Does this system have onboard or seperate video card? Onboard uses system RAM. Loading graphics over text is a massive increase in memory usage.

[aedipuss]

the symptoms to me indicate a bad video card, not eliminating it. the old vga subsystem on all v cards that allows things like the bios to display doesn't need a driver, but the main portion does, and that's when the system is crashing.

[RabidDog]

Disks may be ok to Boot from, but a scandisk is free and easy ..maybe some corruption. re-install OS from your last backup?
AGree with aedipuss. could easily be your gfx card..

[Seeker47]

Some good leads to follow up on. Thanks much to all ! I will update this when I get some time to do the further testing.

This is the Shuttle SN27P2. (I can quote the proprietary MB model # later, if it matters.) A few of their models had built-in video, which you disable in BIOS if you'd rather use a particular higher-performance graphics card. I believe this model does not have any built-in video.

[Nelson37]

You BELIEVE? Have you tried looking at the outputs on the box, and their respective locations? You don't even have to take the cover off. There is either one, or more, video connectors, and they are either ON the mobo, or in an expansion slot.

Booting from a CD removes the HD from the equation. You do have the HD COMPLETELY disconnected while testing, right? This will not confirm that the HD is OK, just that it is not involved in the current sympton.

[Seeker47]

You BELIEVE? Have you tried looking at the outputs on the box, and their respective locations? You don't even have to take the cover off. There is either one, or more, video connectors, and they are either ON the mobo, or in an expansion slot.

Booting from a CD removes the HD from the equation. You do have the HD COMPLETELY disconnected while testing, right? This will not confirm that the HD is OK, just that it is not involved in the current sympton.

Please give me a modicum of credit here: I've been using PCs (a lot) ever since the original XT (that's an 8086, btw !), have built several from kits and a couple from scratch over the years, changed components right and left, etc. Let me rephrase: I'm close to certain that there is no built-in video in these two rigs, but I'd have to check in the BIOS -- or pull up a specs sheet -- to remove those last few percentage points of doubt on that score. I always know what graphics card is installed. The system that had the PSU burn up had a PX-9600 in it. The working (near-twin) system has an ATI x550 in it. (And -- also btw -- this did not trigger any activation issue.) Expansion slot w/ dual-connectors for either card.

Anytime that I boot up a Linux Live CD, the HDD or HDDs will not be connected. These discs are self-contained: that's pretty much the whole point to them. I also have a sizable collection of boot or repair CDs / DVDs. (Most of them are Linux-based.) Later versions of Hirens are a favorite, since they can scope out the hardware you have and driver-load accordingly, plus the neat trick of being able to take you out onto the internet. That was far from a slam-dunk with the Linux Live ones -- at least without a fair amount of fiddling with settings. Aside from a couple occasions when I tried to use that Nordahl thing, I have not performed any serious repairs on a hard drive with one of these, so when booting those other bootable discs the HDD would likewise not be connected. Such was the case these times, as well.

[deadrats]

i agree with the two or three other guys that mentioned the video card; the only time your pc booted up normally was when you used a text based OS while all the other tests either caused the pc to hang or reboot; if the answer had teeth it would bite you.

[Nelson37]

Well, all righty then, take out the existing video card, then see if there is still something there that you can connect the monitor to. This will require about 2 seconds of physical observation, which is a fancy way of saying LOOK AT THE BACK OF THE FREAKIN BOX. If so, great, test. If not, I guess you could check in the BIOS and see if you can make it appear, but personally I would put in the card from the other pc and test with that, using the Boot CD.

Now, if the monitor just happens to be connected to the VGA port that you can't see until you check in the BIOS, then that brings the previously mentioned memory swap back into play as these particular kinds of ports use motherboard RAM.

[Seeker47]

Well, all righty then, take out the existing video card, then see if there is still something there that you can connect the monitor to. This will require about 2 seconds of physical observation, which is a fancy way of saying LOOK AT THE BACK OF THE FREAKIN BOX. If so, great, test. If not, I guess you could check in the BIOS and see if you can make it appear, but personally I would put in the card from the other pc and test with that, using the Boot CD.

Now, if the monitor just happens to be connected to the VGA port that you can't see until you check in the BIOS, then that brings the previously mentioned memory swap back into play as these particular kinds of ports use motherboard RAM.

No extra or "invisible" VGA ports. No video connectors at all, except for those provided by the graphics card, which would seem to settle the matter. What I was referring to was that some -- mostly older -- Shuttle models, like a 2004 P4-based model I still own, provide onboard video, as a chip built into the MB. Just like a lot of full-size MBs started doing some years ago. THAT is what you can turn On or Off in the BIOS, in those models. I'm well aware that such video chips relied upon system RAM. (Shuttle continued doing that with a few of their models, but they've offered so many models -- both for AMD and for Intel CPUs -- that it's hard to keep track.) But mostly not: most of their audience prefers to select a particular video card. They provide a list of the ones supported for each model, because size and power requirement considerations loom large in a SFF box.

Let me ask a related question: supposing that that PX-9600 graphics card may indeed have been compromised, is there any appreciable risk in placing it into another computer for testing ? Would it simply not work properly, or could it cause some damage ?

But I agree that the next, most direct test would be to place a known-good video card into the first computer. A RAM test would probably be next in line after that.

[Nelson37]

Highly unlikely that it would cause any damage, the only way for that to happen would be some kind of dead short, which has not happened in the current PC so it would be almost impossible.