Dodgy new supply?

[GreatBigHippy]

At my wits end with this, hoping for some help.
Creating a new build and my first attempt failed as mboard would not power up, even the fans on power supply would not come on. Bought a new mboard and everything seemed to be working fine.
a few days later my PC has problems powering up. It would start to power up and then shut down again about 3-15 secs into booting. Sometimes it would then try to restart straight away, other times not.
Moving the PC out of where I had it seemed to fix the problem but now it is happening again.
HAve tried a few different kettle leads but wiggling them in the supply would cause it to power up temporarily then shut down again. sometimes even pressing the top of the case would work.
Now everything seems very dead, only light I have is the network card light, all others are off.
Part of me says this is most proabably the power supply but there might be something I am missing, is it possible that the mboard is shorting against the case intermittanly? Would this cause the same symptoms?
For reference system is,
MSI KT7 mboard,
500w PSU
AMD XP 3000
768 RAM
IDE hdrive
SATA drive
CD/RW drive
DVD/RW drive
Radeon 9600XT graphics.
Any help would be well appreciated.
Cheers.

[david eaton]

A short is a possibility.
Remove the motherboard from the case, and try powering it up on a piece of card. You only need one stick of memory, graphics card, keyboard and monitor connected.
If it gets to POST, the board is OK. Replace the board in the case, making sure that any unused standoffs are not touching the board. ( insulate them with a piece of tape).
If necessary, put paper washers on the used standoffs.

When it POSTs OK, add the drives, one at a time, checking after each one.

[GreatBigHippy]

Just had brief flash of obvious and disconnected the power switch and attached reset switch instead.....
Powered up first time.....
Going to try this for a few days and see what happens, have fixed this problem before only for it to happen again...
Will keep you posted.

[Whyzman]

Also, make sure that your stand-offs are only placed where the motherboard's mounting holes exist. Errantly placed stand-offs can easily come into contact with the copper traces shorting them to the case...

Also, Welcome tohttp://www.pcguide.com/ubb/pcgubb.gif Forums!

[GreatBigHippy]

Quick question, the standoffs are the littlie bumps the mboards earth points screw too right?
Just went through, retightend all the screws and placed a bit of paper on one that might be casing a problem...
Cheers for the advice!

[Whyzman]

placed a bit of paper on one that might be casing a problem...If a stand-off is not aligned with one of the screw holes on your motherboard, you can remove it.

Most often, the stand-off placement by the case manufacturers is random and each motherboard's mounting holes can differ...

[GreatBigHippy]

Ok...
After reading around I have completely dissasemblled the PC.....
Now, I think I may have put a little too much paste on my heatsink... it had a small grey pad on the bottom of it that I accidently removed a little of.. (whilst trying to remove the mythical plastic cover referred to in the coolermaster instructions...)
So have taken off all paste now, I assume the grey pad is a heat transferring material.
Strange thing... my PC was running fine, then about 10-20 mins after boot up, shut down and again same power problem....
Can I insulate the bottom of the board with something and cover everything except the mounting holes?
Whilst it is out of case I might try running it barebones for a bit and see if I get the smae problems... the thing is it is so random that I think I have sorted it then I relax and POW!
Other related matter... Processor FSB is running at 400Mhz, RAM is 333... but set to 333 in BIOS, can that cause these symptoms? IE no power full stop...

[Fruss Tray Ted]

Measure and note the shutdown times. If consistently happening at the same time, repeatedly, check into power down modes for the HDD or similar 'sleep' modes with your os or mobo.

Otherwise do a full scan for malware etal if you haven't already.

[Whyzman]

If you've damaged part of the thermal tape supplied with the heatsink, you might want to consider removing all of it and just use thermal compound (e.g. Arcticsilver). With the default installed thermal tape there is no need to use additional thermal compound.

Although the thermal tape or compound are decent heat transfer mediums, the best situation is to have the processor in contact with the heatsink. There thermal tape/compound is actually there just to fill the gap....not to try and create a gap.

If you take the thermal tape off, you might want to consider lapping the heatsink. This can assist in dropping your CPU temps from 3 to 5 C...

http://www.overclockersclub.com/guides/heatsinklappingguide.php

There shouldn't be any need to insulate the entire underside of your motherboard. Are you sure that your motherboard is designed to fit into the case? There are different size motherboards and cases specifically designed for them...

[GreatBigHippy]

Ok, I think I have it.....
I cleared up the thermal paste that I used before (I think there was far too much!) so that might have solved the problem....
But what I think did it was the fact that when I put in the m-board originally there were 6 screw holes, my case only had 5 matching raised mounting points, the sixth one I screwed into a recessed mounting point, DOH! Obviously in my haste to assemble my nice new PC I had attached this one thus putting my mboard under a little stree and causing an occasional short on that corner.
That corner being the one where the power button front panel connectors were... :(
Oh well, it may not even have been that, maybe just taking the whole thing apart and putting it together again sorted what was REALLY causing the problem.
That is if it is actually solved but I have now had 2 days of error free use!
Cheers for help guys.

[Whyzman]

Sounds like things are just "peachy!" :D

If your case setup is designed for the current ATX motherboard format, the possible stand-off positions in the case should be able to match up to any of the ATX boards (well, maybe in a perfect world! :) ).

Most case manufacturers included additional stand-offs (the Enlights I prefer to use include additional metal and plastic alternatives) along with just about any configuration of possible stand-off positions imbedded into the case...

Sounds like you're on your way....Congrats! 'Tis a very satisfying thing indeed to be the owner of an IBUILTIT computer! ;)