Author Topic: symptoms of mainboard failure? (Read 375 times)

wells · « **on:** March 25, 2002, 02:13:32 PM »

Went downstairs this morning to try and download latest video drivers. Clicked on IE5 icon and computer froze. A blue screen came up saying it couldn't read to the C drive. This is a computer that is left on all the time (since it's connected to a DSL). So, I re-boot, no go. Re-boot again and go into CMOS. It auto-detects the 2 hard drives, so I make sure floppy seek is enabled and set the boot sequence to A, C. Now, on restarting, it detects the CPU, RAM and CDRom, but does not boot from the floppy drive (or any drive for that matter!) with the bootdisk in it. The floppy drive *should* work, since the little light flashes on it when I start the computer. Does this sound like a mainboard failure? I opened the case and double checked all the cables, etc...I dunno what's causing the problem. I hope I don't have to do a major upgrade! argh...

Furious · « **Reply #1 on:** March 25, 2002, 02:30:22 PM »

While in the Navy, we used to do this thing called darkroom troubleshooting.

Turn out all the lights and power up. If something is glowing red, thats the bad part.

Don't know if it will work in your case, but always fun never-the-less.

F.

bloom25 · « **Reply #2 on:** March 26, 2002, 02:05:01 AM »

Without some hands-on troubleshooting time one can't be 100% certain, but yes, that does sound like a motherboard problem. Before I changed the board though, I'd check to be sure you 12V and 5V rails off the powersupply are ok. Your drives use both (and only these two) rails to power themselves. If you have a multimeter, measure the voltage on an extra IDE power connector. The black wires in the middle are ground, and the yellow is 12V +, the red is 5V +. Even though this does sound like a motherboard problem, a power supply failure should not be overlooked. If it turns out the powersupply is working correctly, I'd go ahead and suspect the motherboard at that point.

Puck · « **Reply #3 on:** March 26, 2002, 07:41:56 AM »

Then again, if +5 is dead you won't see the CMOS, and if +12 is dead the hard drives won't spin up. If they're out of spec you'll have all kinds of strangeness

Sounds suspiciously like _something_ on your main board is flaky, whether that's a controler or a bridge or something else is up for discussion. Personally I'd strip everything but the video and minimum RAM off and see what happens, then start adding the disks, then start adding cards and mem.

JMHS

R

wells · « **Reply #4 on:** March 29, 2002, 02:50:08 PM »

Voltages look ok, 4.98 and 12.35

I guess it's a new mobo, probabally why my keyboard was cutting in and out and why I switched to USB keyboard! hehehe

Thanks for the help guys.

Skuzzy · « **Reply #5 on:** March 29, 2002, 03:11:20 PM »

Hmmm,..voltage levels can be fine, but the current levels could be too low. I doubt that this is it, but if you have a spare power supply laying around it would not hurt to check.

You might try unpluggin all your peripherals and powering it up. See if the floppy will work first. Then add in the HD, then the PCI cards, one at a time.

If the floppy boot works, I bet it is power supply.

wells · « **Reply #6 on:** March 29, 2002, 03:54:18 PM »

Turns out it was the primary master drive that was causing the problem. Weird though, why it wouldn't boot from the floppy even with a HD failure? Took it out of the system and now it boots up. Still have the problem of trying to get Windows onto the new drive with USB keyboard! I can't type anything at the prompt! hehehe

Vermillion · « **Reply #7 on:** March 29, 2002, 03:56:55 PM »

Wells, it could be your controller card. Is it seperate on your machine or is it integrated into your mobo?

bloom25 · « **Reply #8 on:** March 29, 2002, 05:18:23 PM »

Wells, go into your bios and look for the "Legacy USB support" option. Enabling it will allow you to use a USB keyboard out of windows.

wells · « **Reply #9 on:** March 29, 2002, 09:20:56 PM »

Thanks bloom, didn't even know that was in there! hehe

Anyway, got the new drive formatted, but I can't get CD rom working to install Windows. I even downloaded the dos drivers for it and installed them, still nothing. Maybe I just need a new CD rom drive!? It's an old Panasonic CR-574. The bootdisk drivers for win98SE won't detect it either (but then they say in the help file that old drives might not work). Oh well, cheaper than a mobo!