Broken Toshiba LCD - have spare LCD but does not work

Hi, my wife's toshiba A100 display is broken - 1/3 of the bottom of the panel is covered in multi coloured lines. When she twists it and flexes it (Argh! it makes me cringe to watch her!!!) it will come back for about a day or until she moves the laptop and it goes again. We have a Toshiba M40 with a same size display that some sites say is compatibale(screencountry.com , however when I swapped them it does not work. There is an extra piece of hardware which I believe is an "inverter" that is just under the lcd display - could these be different and cause the M40 display not to work in the A100 laptop?
The specs from the Toshiba site are identical on both laptops for the display -TFT Active Matrix Colour Display, 15.4" XGA TFT w TrueBrite Technology, Native Res 1280 x 800 x 16.7 million colours.
I have no problems opening our notebooks and replacing/repairing parts (had to reconect my USB ports on one side as the conector came loose, replaced my touch pad when it wore down to the point of non-response, etc) but this problem has me stumped.
Thanks for any help someone can give me