Wont Boot up - Did i fry the mobo?

[Selidor]

Ok so my xp machine wont boot up, as in no signal whatsoever is being sent to the display, despite powering up ok. The Dell diagnostic lights at the back arent on at all, which the manual suggests could be a pre-bios failure.

However, previous to being switched on, I opened up the computer for a good clean and to try to figure out how to remove the heatsink. For the cleaning i removed the fan (separate to the heatsink, the two share a plastic shroud) and front panel, and removed a **** of a lot of dust!

I did give the ol' sink a good jiggle, without actually removing it.
I then fitted everything back together and now this.
Made sure all the interconnects inside were in and swapped the RAM into another slot, checked the VGA cable was working - no improvement. So, did i fry the mobo? I opened her up a few days ago and removed and put back the 56k modem, and it was fine, but i didnt get quite this intimate. In terms of grounding myself thoroughly - I touched the radiator with both hands - it seemed to work for one of the IT tech guys who fixed another computer!

It was working fine before - i did a complete re-format and re-install to get the start up time down to 4.5 mins from a staggering 10.5 mins. I know 4.5 mins isnt exactly speedy either, but the machines stats will probably indicate why thats the best:

Dell Dimension 2400
Northwood based Celeron 2.4Ghz
512mb 333Mhz DDR RAM
40Gb Seagate Barracuda
Intel 845GV with Onboard Graphics
Hiper 460W PSU (this replaced the std. PSU when that gave up the ghost - no problems.)

It had been replaced as the family PC and was sitting idle in the loft for 2 years, so my aim was to upgrade it a bit to learn about PC hardware, but have I fallen at the first hurdle?

 

[Slaymate]

Clear the bios and see if it starts. Take the modem out and try it. Does your PC have 2 sticks of ram? Try it with just one stick, try the other stick. Unplug the drives, one at a time and see if one of them is stopping it. Remove the video card and try it, it won't work but were just looking for something different to happen. Try a different power supply.

 

[Selidor]

Clear the bios and see if it starts. Take the modem out and try it. Does your PC have 2 sticks of ram? Try it with just one stick, try the other stick. Unplug the drives, one at a time and see if one of them is stopping it. Remove the video card and try it, it won't work but were just looking for something different to happen. Try a different power supply.

Well i removed the mobo battery for 5 mins - no improvement. Removed the PCI modem,Swapped the single RAM stick , removed the drives (and their power supplies), Generally tried differenc combinations of things plugged in/not plugged in - still no improvement. Cant remove the Video card as it has onboard video, Dont have another power supply to try out. But both that and the heatsink get warm after turning on, so its not completly dead.

Considering all the problems Ive had with my XP machines, I cant say I wasnt expecting something like this to happen!

 

[kimsland]

Try unplugging the CPU fan, and then turn on for a few secs
It sounds more like a Power Supply issue though

 

[Selidor]

just unplugged it then, the power/loading and keyboard lights breifly go on and off but it refuses to start .
With everything plugged in as per normal there still is a little beep, is that a positive sign? Is Hiper a decent quality PSU brand?
I think its important to point out the last time i used the pc before opening it up, it crashed while running 3DMark 2001 at about 0-9fps, so I guess that might have been the nail in the coffin for the PSU.

 

[kimsland]

I don't know if Hiper is good or not (basically I hate any sales questions)
I go by the wattage and Amps, and even the actual PSU weight (imagine that)

If you have unplugged all internals ie:

• 
  All the associated data cables to the below from the Motherboard end
  Floppy
  Hard Drive
  CD
  Fans
  PCI Cards

And also re plugged in the 20 pin Motherboard power connector
And then try turning on (still with all of the above out, except the 20 pin power connector))
And it still doesn't work, I'd be thinking Power Supply Unit (any cheap one will do for those specs)

 

[Selidor]

I don't know if Hiper is good or not (basically I hate any sales questions)
I go by the wattage and Amps, and even the actual PSU weight (imagine that)

If you have unplugged all internals ie:

• 
  All the associated data cables to the below from the Motherboard end
  Floppy
  Hard Drive
  CD
  Fans
  PCI Cards

And also re plugged in the 20 pin Motherboard power connector
And then try turning on (still with all of the above out, except the 20 pin power connector))
And it still doesn't work, I'd be thinking Power Supply Unit (any cheap one will do for those specs)

The minimum it has to be connected to for it to actually start is the fan connector, the 20 pin power connector and a 4 pin power connector, and the on/off button connector - and it still wont work.
So Ill looks like ill be investing in a new PSU then.

 

[patonb]

Check all the plugs as suggested above.. Good chance you wiggled one just enough that its not propperly seated.

Edit

NVM seems you checked.

when booting with no ram, does it squeel?

 

[Selidor]

ah one question though - does it matter whether the new one is micro ATX or just regular?

 

[kimsland]

ah one question though - does it matter whether the new one is micro ATX or just regular?

Doesn't matter, especially for testing purposes

Also your "minimum" stated above: You don't need to fans connected to have the computer POST