New PC won't start up! Please help!

  s99Raj 23:34 11 Feb 2004

I've just bought a new motherboard bundle from Novatech. (The bundle has code MBB-XB281G if you're interested.) It consists of an Asus A7N8X Deluxe Motherboard, AMD XP 2800 processor, Heatsink and Fan, 512 Mb DDR RAM.
With it I've installed a Connect3D Radeon 9600 256 Mb graphics card.

Since the processor and memory come pre-installed, I haven't touched those. I haven't yet attached the heatsink and fan.

I'm sure I've connected the 230W power supply correctly and all the little pins from the case to the m/b (such as Power LED , Reset, etc.).

I've also connected just a floppy and a hard drive (which actually has Windows XP on it from a previous machine, and which I want to reformat anyway).

Now, the problem I'm having is that when I switch on, the PC seems to start up OK but then switches itself off after about 5 seconds. There are no beeps to be heard. I tried putting a (Windows 98) startup floppy into the floppy drive but that doesn't help. Even if it started up properly for a few seconds I'd know everything was fine and I could go ahead and install the heatsink and CD Drive, etc.but the motherboard seems to go into some sort of sleep mode within a few seconds.

This isn't the first time I've built a PC from scratch, so I think I know what I'm doing. Does anyone have experience of this m/b or can anyone suggest what I might try? Cheers.

  s99Raj 23:38 11 Feb 2004

P.S. I'm off to bed now as it's getting and I'm REALLY tired.
I'll check again for any help from you guys tomorrow.

  woodchip 23:58 11 Feb 2004

Are you trying to fry the CPU NO FAN or HEATSINK

  Djohn 00:37 12 Feb 2004

You "MUST" connect the heatsink and fan before you go any further!

It is closing down instantly because of the rapid rise in temperature.

I hope you have not damaged the CPU. [Central processing unit]. Please connect these either with a heat transfer pad or with paste, [But not both] between the sink and the CPU. j.

  gudgulf 00:51 12 Feb 2004

Whilst this wont affect whether your pc boots or not I think that your power supply is a bit on the feeble side for a high spec pc.

300watts as a minimum.

  gold 47 00:52 12 Feb 2004

As has been said already NEVER START UP A COMPUTER
WITH A CPU WITH NO FAN OR HEAT SINK infact you may have damaged it already PSU seems low on power
you require 350W or above these days.

  hugh-265156 01:21 12 Feb 2004

i doubt there has been any damage caused due to no fan or HS being attached.latest models of amd processors should throttle back and or shut down as do intel cpu`s im told when too hot.

connect your heatsink and fan as above.

you dont want this click here

  s99Raj 06:54 12 Feb 2004

Thank you for all this - I know I shouldn't really switch on without a heatsink and fan. I certainly hope I haven't damaged the cpu like this! But it was on for only literally about 5 seconds before it switched itself off.

Hopefully the 230W power supply is inadequate so I'll go buy a new 350W or 400W power supply and see if it makes any difference.

One question on adding the heatsink/fan assembly : the cpu has four small rubber pads on it on which the heatsink/fan assembly seems to rest quite nicely. The heatsink and cpu then seem to have a very small gap between them. Do I need to use any of the heat conducting paste supplied with the heatsink/fan?

  [email protected] 06:59 12 Feb 2004

"Do I need to use any of the heat conducting paste supplied with the heatsink/fan?" YES.

click here

You should find all the info you need on this site

  s99Raj 18:25 12 Feb 2004

I took the cpu out, gently blew on it and replaced it. Then I added the heatsink and fan and it seems to be working now. Now I'll change the PSU to 400W or 500W.

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