Xbox power problem fan turns on but nothing else

I just got an xbox from ebay. it has a problem with the power. when i plug it in the cooling fan turns on and nothing else. i swapped the power supply and the eject power button. each time i swapped out a part it did the same thing. i cleaned the undearneath it to make sure there wasnt any corrsion. the box is not modded in anyway. there does not seem to be any burn marks or bad soder. the hard drive and DvD drive power up in another box. the ver of this box is 1.0 or 1.1 (i think a 1.0)

any help would be great
thank in advance
mike

 

Is there any LED activity? If its flashing orange/green, you have bad AV cables. Any other colors check error codes, http://forums.afterdawn.com/thread_view.cfm/210562#1173990 The box will power but it will not boot, replace the cables.

 

there is no LED activity at all. the cables are also known good, they are from my other box. it does not boot and so it does not get to the error screen.

 

the motherboard/cpu could be fried

 

is there any way to test the motherboard? is there a way to use a multimeter to find out?

 

btw after doing some reading about the differnce from 1.0 to a 1.1 i know know this motherboard is a 1.0.

 

well, if you getting no led activity and a fan is spining that would tell me its the mobo, you can get a replacement off ebay

 

well if it is the mobo then i guess im out 15 bucks (thats what i paid for the system off ebay). if anyone knows a way to test the mobo please leave the info or a link.
thanks