Lenovo X61 X Series ThinkPad :: Failure After Fan Cleaning?

I just bought an X61 on ebay and installed Mint Linux, VirtualBox and the Win8.1 preview.
 
All was going well, except that the heat worried me. The fan was going, but no air seemed to be coming out, so I followed the service manual and dismantled the whole machine. The area between the fan and the heatsink vanes was completely clogged with oily dust and felt, so I cleaned everything, lubricated the fan and re-assembled the machine.
 
Now it will not turn on. No lights, nothing. I have checked all the internal connectors and all seem fine. I've done this sort of thing often in the past, although not in an X61.
 
The one problem that I encountered was that the keyboard bezel was glued to the case bottom near the LH hinge and in prising the glue apart, I had to break a small piece out of the bezel at the back, and I have reassembled it with a slightly loose rear part of the bezel.
 
So, my question is whether there is some sort of tiny switch in the video cable going up to the screen, and does this have to be accurately positioned wrt the bezel? Also, if I try to glue the bezel back together, would epoxy work with the bezel plastic or is there a better glue?