Funny story. I spent the better part of two hours trying to get my flash corrupted SPI motherboard revived. I dumped my RF2J prog roms, patched them, wrote them to new eproms and put the roms on my board. It showed a checkerboard pattern for a second and then nothing. So I swapped the JP121 jumper to the other position. Same thing. Maybe thinking I had put the jumper the wrong way when I put the board into storage, I then tried it in a different orientation. Same result in both positions.
OK, so I guess I messed up the roms? Dumped my original roms again. Patched them again. Wrote them to another set of new eproms. Tried again. Same thing. I then pulled my working SPI motherboard and then tried the board on that. No change.
Ugh, so maybe the cart is dead? Pulled a Raiden Fighters 1 board, patched the roms and tried that. It boots to a region change screen! (*)
I then put the original roms back on the RF2 cart and tried it on my JPN SPI motherboard. It works just fine.
And the problem?
It's an undumped set
I'll dump the rest of the roms in the RF2J and send them to mame later this week.
(*) Going back to this, I succesfully updated the flash to United States. Unfortunately every time I try to flash my US Viper Phase 1 cart to it the counter gets stuck on 547. I let it sit and then turning it on again it boots to a checksum error. Bah.
There's also mistake in the Mame documentation. For the smaller board SXX2D, there is no jumper for game change. You just swap in a different game and let it flash. The jumper (JP121) is for mono / stereo switching. I attached a scan of the japanese manual taken from
@yosais blog (
link) and translated the key points.