Resolved no video

my friends PC has suddenly decided to show no screen of any kind and has asked me to look at it. well i have and cant find the problem
PC specs are
win7
ecs 6100 motherboard
WD 80gig HDD
4 gig DDR2 pc-2 6400
X600 GFX card

The PC boots up and posts, there is activity from the HDD and it runs fine but no picture

here is what i have done so far to try too route out the problem

Changed GFX card X600 to HD5450 and back then
swapped monitor leads, swapped monitors, tried both the monitors and leads
tried both cards in another machine and they work fine
taken GFX card out and plugged into on board GFX port, swapped leads, swapped monitors while trying on-board, but still no pic


any ideas chaps?

 

ok will try that be back in 5 mins

 

still no video signal but i have now noticed a faint but high pitched whistle coming from it
i've discovered that the whistle was coming from the HDD, ive swapped Hdd's ant it stopped but still no signal

 

hi elmo tried all you said and still no video

 

Are you sure the 2nd PSU is capable of supporting that computer and graphics (in terms of power and connectors) because it sure sounds like a PSU problem.

The thing I would have done first is try another monitor. You did that.
Then you tried the card in another machine and it worked there.

So if you know for a fact the 2nd PSU is fully capable of supporting the system, it is starting to point to the motherboard (or at least a major component on it - like the CPU).

Any beeps?

 

no there are not any beeps come to think of it

 

Well, that may or may not mean anything. Many motherboards come with a little integrated speaker to play BIOS beep tones. Many motherboards don't and expect the case's system speaker to be used. But sadly, since some motherboards started including speakers, many cases no longer include them. So, you may not be hearing any beeps because there is no speaker connected to your board. Check your motherboard manual (I would but I note there are several ECS 6100 models so we need the exact model number).

 

there is a mini speaker plugged in the motherboard
model is 6100pm-m2

 

Well, if you don't hear any beeps, and you are sure you used to when the computer was working right, then that again points to the motherboard (or the power going, or not going, to it).

 

hmm ok well i guess it mean its a new motherboard for him then

thanks for your help chaps