Inspiron 8200 WIll not turn on, will not display on screen either

Hey all,

I've done a lot of digging around the forums in hopes to find a solution for my two problems, have tried every suggestion I have found, and have had no success.  Here are my two problems, any suggestions would be greatly appreciated:

This all started when the screen or video card, I cannot determine which, became faulty.  Last night I took the keyboard out of the computer as well as the base, and examined all components.  Visually, the motherboard shows no signs of any damage, and has not been exposed to anything that would damage it.  Also, I did not observe any abnormalities to the video card either.

I put everything back together, and the computer turned on fine, but did it's usual thing where it flashes the Dell logo and then the screen goes blank.  Normally when this happens I switch it to an external monitor, which it will display on just fine.  This leads me to believe that the video card is probably fine and the monitor is faulty.  In my mind if there was a problem with the video card there would be no display on any monitor.  Am I correct, or not?  Any thoughts as to what to do to get the main display working again?

On that note, to my next and biggest problem currently.

After getting my computer to boot, I then had that thought that since it will display on an external monitor perhaps the internal screen is faulty.  To my luck I have another old laptop that I've been using for parts, and was happy to see that the panels were almost identical.  The cables appeared to connect properly to the other panel.  I installed it, and went to turn the computer on, and...  Nothing

I double checked that everything was connected properly, and it was.

So, I reinstalled the old panel, put it back together completely, double checked all connections and grounds, and it still won't turn on.

I've tried two different outlets, and the LED on the adapter is illuminated, so I know there is power going to the computer.

Can anybody think of what may have happened when I switched the monitors that would cause my computer to not turn on, and a possible fix?  Any ideas are welcome.

Thanks guys!