Processor or motherboard problems?

Hey guys,
One of my buddies bought over a computer to fix...now when i boot this thing up, nothing comes up on the screen just dark...and there is this ambulance sireen sound thats constant. I tried the RAM, and everything is fine there, the processor is in a slot..i took it out...the mark on the fan says intel...in the corner of this it says Asus.....the fans are working in the computer when i start it...power supply also...
Can someone give me any help on this..or suggest me anything that i had not already tried ? thanx

 

Did you check that all the devices like dvd rom, hdd, video card are plugged in correctly?

 

try resetting the cmos jumper,post back if your unsure what or where it is,sounds like your video card is dead

 

yeah did as you said. still the same thing
I tried two other vid cards that i have here that i tested on another computer, and they both work. still that ambulance sound.

 

yeah tried another hard drive in it also

 

Ambulance sound?,can you describe it in as much detail as possible,this is telling us what is wrong with your computer,is it a high low tone,like this- high low high low high low high low,does it carry on forever or does it change at a certain number,also can you find the bios chip near the cmos jumper and post the name of the bios if its printed

 

yeah the sound is high low ..high low....forever

 

Thats a bad or faulty cpu,first check the fan,unplu and reseat it,next theres no way around it remove and reseat the cpu,reinstall the heatsink with some fresh thermal compound and try,if it dont start you need a new cpu

 

when you reset the cmos jumper,also unplug the comp from the AC and remove the cmos battery to fully make sure its resetting