Pc won't boot

Friend has a pc that won't boot.
When you push the on/off

the pc powersup, the harddrive spins but there's nothing being displayed on the screen.

Don't now where to start looking. Any Ideas?

OK, first things first... is there any beeps?
Do the keyboard lights flash?
Does the cpu fan spin?

If no, then try an make it beep.. powerdown, remove the video card and all other cards, also unhook the hard drives/cdroms from ide port and power it back up, should beep, if not try removing all the ram next.. if it still won't beep then you have either got a dead board, a shorted board or a dead processor.

Or the PC speaker isn't connected............ :D

possible bad video card. Gotta spare you can swap???

cpu fan is working but there are no beeps

Hmm... Pull all devices out of case - leave only MB,CPU,Videocard and memory.
If still no beeps,then...
1. Pull out videocard - should be one long and two short beeps. If yes - replace videocard, if no ...then...
2. Pull out all memory sticks - should be constant short beeps. If yes - memory is bad, if
no ...then...

Then probably either BIOS chip damaged or somehow erased,or CPU voltage regulator is fried.
In first case You can try to reflash the BIOS chip in another motherboard using the latest Uniflash utility (latest version is V1.25),available <a href="http://www.pppr.sk/rainbow/programs.html#UniFlash" target="_blank">here:</a>
My topic "How to reflash bad BIOS chip" is <a href="http://forums.windrivers.com/cgi-bin/forum3/noncgi/ultimatebb.php?ubb=get_topic&f=17&t=005214" target="_blank">here:</a>

In last case I would check all the voltage regulators using multimeter.
Of course,it can be also fried CPU itself, but it is rare thing...
Good luck! ;)

Here is my theory:
My computer died on me almost 2 weeks ago, it was my Antec power supply! I ordered a brandnew Enermax 550W and connected everything up ready to power up my system. When I hit the power switch on my computer all the fans started to spin, the lights on the case came on harddrive, cd-rw etc... but nothing on the screen just like your friends pc. I tried evrything, even rebuilding my entire system but I could not get anything on the monitor. I even tried booting up with no memory installed to see if there were any beeps(no beeps were heard). I almost wrote my system off as being damaged beyond repair but in one last ditch attempt I fitted an old ATX 230W PSU from an old Time computer I had knocking around the place. It worked! The machine powered up as normal and the monitor sprang back into action. The brandnew Enermax was faulty. I obtained an RMA and ordered a new PSU from Pc Power&Cooling in the USA. It arrived 3 days later and everything now works fine. My opinion is there could be some fault with the ATX power connector on your friends pc so my advice would be for you to try a known working PSU from another computer before you try too many other fixes first. Although it might not make sense as a fix to the issue you have made this post about but I will repeat my suggestion, CHECK OUT THE PSU! Don't be fooled by the fact that some power is getting to the system so the PSU must be working OK.


PS:If it is the PSU please post back here and let me know. Thx.