New motherboard blowing my circuit breaker

[Freyland]

Hi

I just purchased a MSI K7nxx Platinum mother board to use with my Athlon XP 3200+ and Gainward 5700 Ultra vid card.  The powersupply is a new 480 MW and was not the problem with my last motherboard.  My problem is two-fold, and perhaps related.

1) During the boot up sequence, at no specific point, but always while I am still in 'Dos text', the computer just shuts down.  I have to press the circuit breaker on the Power supply before I can try to reboot.  One possible culprit is the vid card since it requires a power cord all of its own, but again the PS is 480 MW and the card was not shorting out the previous MB configuration.  

2) Both CMOS and the boot sequence acknowledge that I have a hard drive in the Master 1 slot, but when I try to boot from a Windows Boot floppy (because I need to repair a Hall.dll file), it will not recognize c: d: or anything else.

Are these issues connected?  Are there common things that cause PC's to set off the circuit breaker?  Please aid me if you can.

Thanks!

Jonathan

[Freyland]

Okay, I think the Hard drive recognition problem is because I am making a MS-Dos boot disk and it provides a dos prompt only (though it seems odd that it would not allow me to see other drives)

I replaced the 5700 Ultra with a Radeon 9000 I had lying around (which does not require additional power) and the PC still powered off, so its not the 5700 Ultra card.

Still very lost.  

[egrudzin]

Your power supply could be bad.  I had a PC that would just shutdown randomly and sometimes would not turn on at all.  Replaced the power supply and it was fixed.  I have heard of cases where some power supplies were just incompatible with certain motherboards despite the ratings.  Also make sure you have made all the connections properly.  Most new motherboards have two connecters:  a larger (20 pin?) connecter and also a smaller 4 pin auxilliary connector.  Make sure these are plugged in.  When trying to get the system to boot remove all non-essential devices from the PC.   This means fans (not the CPU fan) drives, expansion cards etc.  Only plug in CPU, CPU fan, RAM, vid card and see if it will boot.  Then add other devices one at a time.  I have seen a case where a bad system fan caused a PC to not boot properly.

I assume your hard drives have Windows XP or 2000 on them?  If so they are probably formatted in the NTFS file system.  DOS only recognizes disks with the FAT file systems.  So when you use a DOS boot disk none of the NTFS drives will be mounted with drive letters.  If the drives are blank then they won't be mounted in DOS either.  They have to be partitioned and formatted first.  Windows setup will do this for you.  If the drive shows in the BIOS then it is there.

Another thought.  When you physically installed the motherboard did you reconfigure the stand-offs (where the screws go in) in the case to match the new board.  You need to make absolutly sure that there are stand-offs only where they line up with the mounting holes on the board.  Extras may touch the the board and short it out or cause power problems.

[gameoverman]

My technique with PC problems is to disconnect EVERYTHING that isn't needed to boot to your desktop.  Since you have your OS installed, this means if I were you, I'd boot up with only my harddrive and vidcard installed, no cd/dvdrom or floppy. No soundcard or other peripherals.

Just the mouse, keyboard and monitor should be hooked up to your computer during troubleshooting.  If possible, I'd hook up your surge protector(or equivalent) to another outlet too. Maybe try booting to safe mode, using F8 too.

[Freyland]

Gentlemen, thank you.  Egrudzin, that was a particularly well written post.  My guess is your latter insight, as a faq on the MB website suggested this possibility also.  A question on this statement of yours:

When you physically installed the motherboard did you reconfigure the stand-offs (where the screws go in) in the case to match the new board. You need to make absolutly sure that there are stand-offs only where they line up with the mounting holes on the board.

How exactly do I ensure this?  I mean, the MB previously had one white plastic doohickey (standoff?) and numerous screws, and I simply put the white doohickey in the same place and the screws in the same place.  Could you clarify for me?

I am unable to work on this until I return from my Certification Boards, but if you check back probably late EST on Tuesday, I hopefully will have an update.

Thank you both!

Jonathan

[egrudzin]

I'll try to explain this as best I can.  If you remove the motherboard from the case you will see a whole bunch on screw holes on the bottom of the case.  Look at the motherboard and you will see holes that go thru it.  Depending on the size of the board there are ususally 6 to nine of these holes and they are usualy along the outer edge of the board and on the corners.  If you place the board in the case you will notice that the holes in the board line up with some of the holes in the bottom of the case, note which holes these are.  Then take the board out and screw the standoffs into those holes in the case only (the ones that line up with the board)  The standoffs raise the board up off the bottom of the case so it doesn't short out and lines up properly with the back of the case.  Standoffs usually look like hexagonal brass pieces with threads on one end and a screw hole in the other.  The white thing you mentioned will work as well but I usually use just one of those and the hex peices for the rest.  The white thingy helps hold the board in place as you screw it down.

The reason this is important is because the holes in the motherboard are insulated so they do not touch any of the etchings on the board.  That way the standoffs can touch the hole without shorting the board.  If you have a metal standoff under the board that doesn't line up wtih a hole it can cause a short in the board and possibly permanantly damage the board.

Sorry for the length, I just wanted to make it as thorough as possible.  You may also want to check the motherboard manual as it should have mounting instructions and will probably have pictures of the parts as well.

[Freyland]

Well, I blew 3 hours on Wednesday night making certain I had every inch of the MB protected, but I am still failing.  Interestingly, I managed to extend the crash time from 2 minutes to 8 to 10 minutes.  However, I just dropped it off today, just not enough time to mess with it anymore.  We'll see what they come up with.

Jonathan