Heyo again! Just a couple updates:
I have a new YouTube channel now for LCD gameplay footage! So far I have footage for Sonic 3, 3D Blast, and R.
I also have a manual for 3D Blast now, courtesy of RinShiro on Reddit ("Rin-Dev" on the Internet Archive).
In other news, I'm having some technical difficulties with two other LCD's... First, I got a hold of the Tiger Sonic Spinball one you were looking for. It turns on just fine, however, there are some errors with the lcd display --- when certain elements are lit, it will also light other unrelated elements. So I can still playtest the game for you and capture footage, but it will have these occasional errors. Good news is at least every one of these graphical errors is consistent and therefore predictable. If this already-existing video isn't enough footage, I can playtest any additional scenarios you might need --- just let me know.
Second, I have two new-condition LCDs of SegaSonic the Hedgehog, both of which don't work, and I'm looking for advice on what to do to see if they're repairable. They're very rare, so I'd love to capture footage of them if possible. I replaced the batteries in both, but neither will turn on aside from some beeping sounds to indicate that at least something is working. I took one to a guy who knew a guy who was willing to look at the circuit board, and he said he could get it working just fine except the lcd screen wouldn't display anything. So I don't think it's screen rot since I can't get anything to light up in the first place, right? Is this a known issue with LCDs? If you have any advice, please let me know. Thanks!