i232 on the main board has been found to not take when soldered at the factory. The bakeing process is suspect.
See the link below for details.
To check yours, shoot the i232 (printed on the main board) with some cold spray (electronics shops carry the product) and then plug it in and try it. Mine will work great right after shooting the chip but within a minute when it warms back up, it fails once more.
Still looking for a place who can re-solder the chip :)
Good Luck
http://www.dellcommunity.com/supportforums/board/message?board.id=dce_W1700LCD&thread.id=12588&view=by_date_ascending&page=4
Kevin St.Laurent, August 2007