Hi all,
Currently have a Twister that I've had for a couple years, the spinning disc is not spinning, which seems to be a common problem.

One solution was to replace the main ROM, which I'm finally getting around to replacing. I initially had trouble pulling out the existing ROM chips which is why I took so long to replace as I didn't want to break anything. Finally was able to figure out how to extract existing chips without causing damage.

Here are the chips I got:
TWISTER (SEGA) EPROM U210 GAME A4.05
TWISTER (SEGA) EPROM ROM0 DISPLAY A4.00

I replaced both in the game, but when I turned back on on game doesn't appear to boot. PF Lights come on, but game doesn't start. Removed the new main ROM (but left display) and replaced with original, and game booted after asking me to open door.

Question 1: Is there something I should be doing to help it boot with new ROM chip, or is it missing something else that needs to be added for the new ROM chip to work?

Question 2: Aside from display working as expected, how can I check that updated ROM is functioning properly, what has changed?

Any advice appreciated.
Thanks.

twister1 (resized).JPG

twister2 (resized).JPG

Thanks PM,
I'll try to post a picture tonight.

Regarding the chip, I don't believe I installed it incorrectly, I was aware of the notch, but I can't definitively say I didn't. Maybe I'll order a new chip to be sure, only $10. Should I grab new sound chips as well? I'm assuming there is a breakdown somewhere showing what changes/fixes are in each ROMset?

Thanks,