HDD Light on all the time and no boot

Double check the jumper settings ( unless the drive  is SATA )

Can you boot from CD?

Drive set to master. Same with drive in or out.

No boot from CD.

There is no activity at all from the bios.  No booting at all.

Try resetting the CMOS using the motherboard jumper or by removing the CMOS battery for 10 minutes.  Installing a new cpu sometimes requires this.

I have tried resetting the CMOS.

I have not however tried removing the battery but I will right now.

THis is a new build system so bios should be OK should it not?

Well thats what I was thinking as it was straight out the box.

I did the usual and used tested graphics cards and correct ram and the processor is supported.

I had my wrist band on throughout the assembly and took all necersary precautions.

I've built loads of PC's but never had a fault like this so thought I should ask just to see if I was missing anything.

I have ordered a new board and will see what happens.

I'll let you know.

If no activity from BIOS . . the board is likely dead

One other thought . . there is a four pin connectof on most boards . . you did connect the four pin from the power supply?  Not doing that will cause the behavior you describe

Yes and I have fully tested the power supply as working

soundsl like the board

I've seen the HDD light stay on if the IDE cable was backwards, though it's less likely with a newer system since they're keyed now to prevent this problem.

Try unplugging all the IDE cables from the motherboard. Unplug all the power connectors from the drives. See what happens. If the light stays on, power it off, then remove the IDE LED lead from the motherboard and try again. It's possible that it's connected incorrectly (or the LED in the case is defective and shorting something out).

What kind of processor and motherboard is it? Are you sure the power supply is strong enough? Did you make sure (if it's a P4) that the four pin P4 connector from the power supply is connected?

One more thing I just thought of. Make sure nothing's shorted out underneath the board. A screw down there or a mounting post in the wrong position can cause all sorts of grief.

Have tries with no drive cables sconnected and they are keyyed anyway.  Also checked for shorts but nothing.  It is a pentium D processor and I have tried with a higher power power supply with the same results.  Could be a defective LED but the case was the original and worked fine before so I don't think that it is that.

The P4 connector is installed and I have tested the power supply OK.

try booting with the minimum connected :
mobo + cpu + 1 ram stick, video card, --> does it give a display?
you can also test the parts on another PC, to be sure.
--->since you did not upgrade the disk, if it contains an XP install, you cannot just switch it to other hardware; look here :  
http://www.michaelstevenstech.com/moving_xp.html                  Moving XP
http://support.microsoft.com/kb/314082/                            "        "
http://support.microsoft.com/kb/249694                          "         "  

I am aware of this but changing the IDE Drivers to the Micrisift default should fix this.

I have tries all possible combinations and still nothing.

The only thing is that the computer powers on straight away which I'm worried could mean the processors gone but then it does it without it installed.

Once, in my earlier days I installed a socket 754 reversed and nothing happened on the screen.  Put it in right and everything fired up.  Secondly, I also once had an earlier athlon socket A chip that had a very hard to see chip off the processor and again it would not fire up.  Double check your cpu and break out a magnifing glass before you totally determine that it is a motherboard issue.

Ryan

Sorry for not getting back to you all but the mobo was doa.  Thanks for your help.