Dead motherboards ?

I have 2 dead 14 inch Inspiron 5100s with 2 different video cards, can someone tell me the name of these cards:
AMDW003C000 030419REV:A00
AMDW001C000 030523REV:A00 (Is this ATI Radeon 7500 16 MB)?

I have only one 14 inch screen which I have tried on both machines, the screen appears dead.

The 5100 with the AMDW003C000 030419REV:A00 video card: Will not post up on a exterior monitor. Turns on with power cord for 30 seconds then fan turns off, green power light stays on, fan comes back on and cycles as normal, Battery will charge, there is power to the DVD player. Have swithched out memory, hard drive, battery. Have cleaned out heatsink, put new thermal grease on cpu chip and locked it.

The 5100 with the AMDW001C000 030523REV:A00 video card: Will post up using a exterior monitor. It starts up with battery only for 10 second then the fan shuts down, 20 second later the fan comes back on, one beep, posts up but won't go any farther, fan cycles normaly. There is power to DVD player Bios says no hard drive but hard drive is known good. Have swithched out memory, hard drive, battery. Have cleaned out heatsink, put new thermal grease on cpu chip and locked it.

Could both motherboards be bad?
I don't have any way to check if screen is good or bad. Anybody know if I could plug in a CPX, CPI screen to see if that came on, just laying it horizontally.