Inspirion Notebook Sometimes Dead

Got a question ,

 

 

I have a Dell Inspirion that is still under warranty, my son put some stickers at the bottom of the laptop for identification at school and when he removed them he pull off the Service Tag sticker and can't locate it.  Now (wouldn't you know it) the laptop won't power on.  Is their anyway the tech can pull the service tag number off the system without the power?  Is the service tag located anywhere else on the unit so I can call in and set up service call.

 

The unit is in his name and was transferred to him some time back.  He's brought it home while he's on vacation to see if I can get it fixed for him.  With no power, I can't tell what wrong with it.  I have tested the harddrive, memory modules, and battery and all seem to be ok.  I think perhaps the power supply or motherboard may have gone out.:robotsad: