iPad wont power on, charge, connect to iTunes please help?

Hi there guys,

I have been asked to look at a colleagues iPad 1st gen 3g 32Gb basically this has seen better times an has been dropped on a few occasions, there is a small hairline crack / scratch in the glass not too fussed about that.

But the device does not appear to charge (screen stays blank) when plugged into a PC USB port neither does the computer acknowledge the connection. and does not appear to charge when connected to a mains adapter (screen stays blank) again no signs of life. Also cannot power on the device with the power button (assuming the batteries may be dead) can not even attempt to get into restore mode again due to no power. I haven't attempted to open the device yet so basically I am looking for pointers to help me troubleshoot this issue ie the dock connector, dead batteries or could the issue be elsewhere.

Any help will be really appreciated

Many thanks

Shane