Author Topic: Advice needed, homebuilding problem (Read 393 times)

mkuebeler · « **on:** November 03, 2002, 12:06:25 PM »

I am building a new PC, Pentium 4 system. Everything seemed to be hooked up properly. Went to power up for the first time with case open so I could verify CPU fan starting up, etc. Northbridge fan came on, the CPU fan looked like it was just starting to turn when then there was a pop and a flash, I'm almost certain from the power supply. I was looking directly at the CPU fan and caught it out of the corner of my eye. I think all power was lost at that point, but I was in a hurry to pull the power cable out.

So, does this sound like a blown power supply? It's an Antec 330W unit, came with the Antec case I bought for the new system.

Advice? Suggestions on next steps? This is the fourth PC I've built, never had a problem like this.

Innominate · « **Reply #1 on:** November 03, 2002, 12:23:09 PM »

Try a different power supply?

If you're brave you could open the power supply up, and look for anything obviously wrong.

A pop and a flash is bad.

mkuebeler · « **Reply #2 on:** November 03, 2002, 12:54:31 PM »

Quote

Originally posted by Innominate
Try a different power supply?

If you're brave you could open the power supply up, and look for anything obviously wrong.

A pop and a flash is bad.

I'm wondering now if a 330W PSU is even enough to drive this system. I browsed the Usenet group alt.comp.hardware.pc-homebuilt and it seems like the usual recommendation is 450W or higher.

eagl · « **Reply #3 on:** November 03, 2002, 10:05:04 PM »

I'd suggest a new power supply and unmount/remount the motherboard with special attention given to making sure you don't have any short circuits.

The exact same thing happened to me with a brand new athlon motherboard/cpu combo. I tossed the power supply in the trash, disassembled the ENTIRE computer and laid it out on the floor, plugged everything back in with it sitting on cardboard using a new power supply, and tested it that way. After verifying that all the parts worked, the pieces all went back into the case.

Sure, it was a major investment in time but I didn't have to buy any more parts either.

bloom25 · « **Reply #4 on:** November 03, 2002, 11:58:02 PM »

Probably just a bad power supply. Do not open it, you'll break the seal and probably not be able to return it. A 330W Antec power supply is plenty for your system.

mkuebeler · « **Reply #5 on:** November 04, 2002, 05:15:50 PM »

Quote

Originally posted by eagl
I'd suggest a new power supply and unmount/remount the motherboard with special attention given to making sure you don't have any short circuits.

Apparently what happened was that I didn't get the floppy drive power connector on right (it was offset by one pin), and I've read accounts of this causing a short. Should've checked it better. Tried to power up the system with floppy disconnected, but no juice at all now, so I figure I kilt it dead. New PSU is on order.

Booky · « **Reply #6 on:** November 09, 2002, 05:36:35 AM »

Before you turn on your system I want you to check your motherboard mounts. The Floppy could cause a short but not enough to blow the PS. Antec makes damn good PS so IMO It was either a outright bad PS (very rare from Antec) or your MB is shorting out with the case. I can't count how many times people bring their home built systems in saying it wont boot, or it made a shorting noise (pop) and it turs out that the pre configured studs are in the wrong spot for that particular board. So just to play it safe, I ask again for you to make sure all your mounts are in right and not hitting anything.

One guy RMAed 3 MB before bringing his in and me seeing the black pouder marks on the case benieth the MB:eek:

Booky

Booky · « **Reply #7 on:** November 09, 2002, 06:11:44 AM »

Oh and about the 330W not being enough question. I think that since it is a Antec PS and they do not hide behind loops like other PS companies I think 330 should be fine. Only exception would be with a 2.6GHz chip, a GF4 4600, 1GB memory lots of HDD CD-ROM's and such.

The reason people say to get a 400+ is because they refer to brands that don't put out as much as they say they do. For instance my Enlight 300W puts out a more stable flow than my POWMAX 400W. You wouldn't think it was this way but if you want some tips on Power supplies read this little article over at THG.

http://www.tomshardware.com/howto/02q4/021021/index.html

I think it will give you a nice understanding of what to expect and what you need when building systems of different uses.

Booky

mkuebeler · « **Reply #8 on:** November 09, 2002, 08:02:09 AM »

Quote

Originally posted by Booky
Before you turn on your system I want you to check your motherboard mounts. The Floppy could cause a short but not enough to blow the PS. Antec makes damn good PS so IMO It was either a outright bad PS (very rare from Antec) or your MB is shorting out with the case. I can't count how many times people bring their home built systems in saying it wont boot, or it made a shorting noise (pop) and it turs out that the pre configured studs are in the wrong spot for that particular board. So just to play it safe, I ask again for you to make sure all your mounts are in right and not hitting anything.

One guy RMAed 3 MB before bringing his in and me seeing the black pouder marks on the case benieth the MB:eek:

Booky

Actually system is already up and running with a new PSU (Antec True Power 480). I was very careful when I installed the MB, so I was sure that didn't cause the problem. Only change was taking more care hooking up the floppy this time. Perhaps the PSU was indeed defective and should've been able to handle an improperly power connection to the floppy. We'll never know. What is really ironic about this is that I came very close to not even putting a floppy drive in this system! Next system (in two years or so) will definitely not have a floppy.

qts · « **Reply #9 on:** November 09, 2002, 05:00:43 PM »

Should this sort of thing happen again to anyone reading this thread, I would strongly suggest removing the motherboard from the case and powering it up seperately, on an insulated board.

As for opening the PSU, be sure to leave it off for 24 hours first to give the capacitors time to discharge.

capt. apathy · « **Reply #10 on:** November 09, 2002, 10:32:21 PM »

unhook your power suply from everything, then power it up to see if it's at least working.

btw I had a simular thing happen the first time I installed a motherboard. I missing one of the plastic pins that insulate the board and it grounded to the case. toasted the board and cpu.

batdog · « **Reply #11 on:** November 11, 2002, 07:01:04 AM »

Guys...rem to get a voltmeter. Something cheap will do. If something like this happens you can test your voltage coming from the PS then.

xBAT