system repeatedly restarts after post

[palkot]

I just finished building a system for my brother - here's the problem.

Well, the first problem I have that I've circumvented is that the power switch doesn't always work. When it's pressed, the RAM LED on the mobo comes on and the fans kick on for an instant- that's it. None of the seven fans in the case run, no beeps, no hard drive. I've figured out that if I hold in the power switch until the RAM LED goes out and then hit it again, the system turns on fine- most of the time.

Anyway, the real problem..

The display comes up fine, I set up the BIOS the best I know how according to the book, memory check OK, it sees all the drives, lists the PCI config whatever and then the screen goes black and instead of the Windows XP screen, it flashes a blue screen error message so fast I can't read it (it would really help if I could) and then the system restarts. It does this over and over.

The only thing I can think of is that I pulled the hard drive right out of an old Althon 750MHz system and stuck it right into the new one. Should I format and/or reinstall because the system's components are so different?

Here's the specs:

Gigabyte P4 Titan Series 875P FSB 800 Dual Channel DDR400 AGP 8X
P4 1.8GHz @ 400MHz FSB (mobo supports 400MHz FSB)
2x 512MB DDR400 RAM = 1GB
Leadtek WinFast A380 Ultra TDH 256MB DDR GeForce FX 5950 Ultra

Thanks in advance for any help!

[BigBlue66]

You will have to reinstall XP, since your harddrive has drivers for an AMD chipset, and you're going to an Intel chipset.

No way around it, I'm afraid.

[palkot]

Makes perfect sense. Thanks!

[palkot]

Oh yeah, and about the power switch- anyone have a thought on that?
Is that dangerous? Is 350 Watts enough for a P4 1.8 GHz, two case fans, and the GeForce FX card? (besides the HDD, CPU fan, and two optical drives)

However it was giving power-on problems when I substituted an older VGA card.

What could cause it to behave like this?

I was working on an older system a while ago.. the problem was that it didn't turn on. I set it up, hit the power switch and nothing happened. So I left it alone to grab a bite to eat, a full 10 minutes later it just decides to turn itself on. And that was a soft power switch. I still don't understand that.

Again, thanks for any thoughts.

[ski]

Clear CMOS with a MB jumper(see MB's instructions) if that has not been done.
If the startup problem still happens, then disconnect the power-on button's wires from the MB connectors, and see if it starts up by momentarily shorting the connectors with a screwdriver.
If it does, then replace the power-on button assy.
If that does not work, then there may a MB problem.

350 watts may be ok.
If it's not enough juice, then you have problems once everything is up and running, like automatic restarting, crashing, freezing, etc.

[Whyzman]

I'm wondering if you have the power button connected to the reset button and visa versa...

Reading the connectors on the motherboard is usually pretty difficult...

[palkot]

No, this motherboard is pretty well marked - the best I've seen.

I ended up ripping the mobo out of the case, reseating the processor (at the advice of a friend)?, and starting it up bare by shorting the pins with a screwdriver. It started perfectly 3 times in a row.

I put the mobo back in the case, nothing.

I'm starting to think there's a short somewhere, but what could be shorting it out? The only thing that touches the chassis are the I/O ports. The one optical drive comes mightly close to a big capacitor, but those are coated in plastic.

(I also pulled a great stunt and plugged the floppy drive power cable in shifted one pin to the left. Please Please Please double check this when you install a floppy drive. The indents on the floppy power cord are NOT idiot-proof. I've put dozens of floppies in cases and I got sloppy. Also, do not do this to find out what happens. You'll be short a floppy power cord and a floppy drive.) (EDIT: oh yeah, and it was plugged in wrong for a while and nothing happened. when i took the mobo out it burned so triple check it)

[ski]

Place the MB on a piece of cardboard when it's in the case. If that works, then the MB is shorting out.
The most likely causes are one of its circuit traces is touching a metal standoff, or there's a stray metal object(standoff, washer, etc.) somewhere in the case.
The fix for the 2nd cause is obvious, while the 1st cause can be fixed by making sure that all metal standoffs are installed only where the MB has mounting holes. If some are installed where there are no holes and the MB needs suppoort in those areas, then replace them with plastic standoffs.
If metal standoffs are installed only where the MB has mounting holes, then install paper washers(manila folders make good ones) between the MB and the standoffs.

[Paleo Pete]

I'm starting to think there's a short somewhere, but what could be shorting it out?

The motherboard itself. Get some cardboard washers from a computer shop, they're cheap, and put them on the screws that hold the board into the chassis. Usually that will fix it although I've had to use them both there and under the motherboard a time or two...boy is that a pain...
Is the switch problem taken care of? I had the same idea as Whyzman, I thought it was connected to the reset pins, which will cause exactly what you described. Even boards that are marked use tiny print, it's very easy to mis-read them.

[palkot]

OK, figured it out.

A back panel with 2 USB, firewire, etc. came with the mobo. There were two plugs to the board. Right beside these two ports on the board were the two more ports for USB.

The pin configuration for this IEEE 1394 port matched the USB pin configuration on the plug, so I mistakenly plugged it in there because it was right beside the port for the firewire plug.

That wasn't where it went, so that's what caused the system to act up like it did. One of the USB ports was for the front two, one was for the back two. I had only been using the one, so I put the back where it was supposed to go and badaboom.

Also, about the hard drive (from way above), all I had to do was repair the installation with the XP CD. That thing is pretty smart, it just deleted the mismatched files for the AMD chipset and copied the Intel ones on. No need for reformat, it took about 30 minutes.

So now the whole thing works perfectly. Thanks for all the support for my silly mistakes!

[ski]

Glad to hear that you solved your problems, and thanks for posting back with the solutions.

[Whyzman]

Originally posted by ski
Glad to hear that you solved your problems, and thanks for posting back with the solutions. I'll second that! :cool: There's a wealth of learning to be had from a solved problem! ;)