DV6000 palmrest/keyboard surround

I have had my pavilion DV6101 for 2 years. I noticed at the beginning of the year that the palmrest/keyboard surround was starting to crack on the left and right sides and that the crack was spreading. A few weeks ago I got a surround from ebay for the fully featured DV6000 model which does fit my model pavilion. I had to almost completely strip the laptop to swap these parts over, when I had reassembled my machine I found it was not working. I decided to take it into a repair shop. I heard back from them this morning and they reckon that I have fried the machine because the cover I have put on is metal (aluminium I think) and the original was plastic. Can this really be the problem though, as the palmrest are exactly the same size and shape, would the higher spec model have extra sheilding on the circuit board to prevent this from happening? I thought that it may have been a problem with the ribbon cable. Before I took it into the repair shop it did come on once before I put it back together, which also makes me think that the problem is not with the mb. Does anyone have any ideas on this? could it be the difference in the materials that has done this?
I wasn't going even going to bother trying to have this repaired but my girlfriend insisted as she wanted it for looking at the internet (ebay and shoe shops)