Lost Display on acaer aspire 5720?

Help?,
Can any one help please, acer aspire 5720, the display lost some colours while my son was away at Uni, i told him that the lcd screen lead might have come loose, (it had) he pushed it back in & as he tested the display before putting it back together, he let the metal on the screen short out on the button board, now he can only get an external monitor to work, i've replaced the screen/lcd lead & the inverter, there's no evidence of any burn blow marks on the mobo, all traces seem to be intact. the laptop is still fully working on the external display, is it posible to rewire the lcd to the vga out on the mobo, or does it use some kind of of display controller,any help would be great, Cheers Terry Sim