hello,
the problem you will have is entering the service mode, without a service remote especially because to enter it you press menu on the set and menu on the remote, sometimes the wires get trapped that connect the function buttons at the top of the set, and are remote functions odd too?
i can post you new firmware but you need a program called lgterm, programing is done via a pc with a 232 lead and this must be a twisted pair lead, but as i say your problem will be entering the service mode.
you must hold the buttons in (menu and menu) for at least 8 seconds. if you get into service, try before we go any further and ill post explicit details for updates, failing that ill sort a pcb, reasonable!
tony walker