I wonder, would one of these new 4" screens give better picture quality? I'm assuming that the image persistence you get on a regular LT screen must be down to the more primitive LCD tech of the time?
So many questions
Better picture quality out of the new 4" LCD, as opposed to the stock NEC LCD? If you feel like doing it yourself, first, ask yourself the following three (3) questions:
1.) "Do I know what the difference between composite and RGB video is?"
2.) "Are my hands steady?"
3.) "Do I know how to use a soldering iron?"
If you answered 'no' to any of the above questions, then I would kindly advise you to consider looking into what PunkicCyborg suggested and follow up on that, making sure to note the difference between RGB out as opposed to composite out going to the 4" screen before asking what you need of the prospective PC-Engine LT repair specialist. Here is a link to a video that provides a visual example of what I am referring to:
If you absolutely want the best picture quality, and you feel comfortable tinkering around with a rare PC-Engine LT, you're probably going to have to read this doc:
http://www.gamesx.com/wiki/doku.php?id=hu6260_netlistThen re-visit the PCEGT LCD replacement project page, read it and see if you can do better than that. According to my perception of how it was done on the PCEGT LCD replacement project page, the poster, woshizyt, used the replacement LCDs' stock driver board to convert the HU6260 chips video signals to what would appear as a composite video signal on the new screen. I could be wrong but that is what appears to have happened to me. My guess is that it is possible to get true RGB out to the replacement LCD screen.
Safe Care and Take Travels,
Tlaloc