- Joined: 01 Mar 2020
- Posts: 18
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Worthington FM board - cannot get region switch to go into JP mode on SMS II
 Posted: Tue Jan 09, 2024 5:21 am
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I have a NTSC SMS II with Tim Worthington's FM board installed, but I am having a problem with the JP mode.
The wiring in place on the FM board attached to the switch and it will only enable the FM when in positions 1 or 3 with PSG only sound in position 2 in the middle. This was check using Wonder Boy Dragon's Trap as the system in that mode would normally boot up showing Mark III but it only shows the normal SEGA BIOS logo as normal and of course has the normal title screen and no FM music being played.
Disabling pin 19 off the 5216 IC and attach a wire from that back to the IORQ# pad on the FM board but just results in the SMS not wanting to boot at all with that pin disconnected out of circuit as stated in Tim's guide. But again, that prevents the SMS from even booting at all.
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- Joined: 01 Mar 2020
- Posts: 18
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Posted: Wed Jan 10, 2024 4:14 am
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Perfect! wrote I have a NTSC SMS II with Tim Worthington's FM board installed, but I am having a problem with the JP mode.
The wiring in place on the FM board attached to the switch and it will only enable the FM when in positions 1 or 3 with PSG only sound in position 2 in the middle. This was check using Wonder Boy Dragon's Trap as the system in that mode would normally boot up showing Mark III but it only shows the normal SEGA BIOS logo as normal and of course has the normal title screen and no FM music being played.
Disabling pin 19 off the 5216 IC and attach a wire from that back to the IORQ# pad on the FM board but just results in the SMS not wanting to boot at all with that pin disconnected out of circuit as stated in Tim's guide. But again, that prevents the SMS from even booting at all.
Alright, got this figured out. Worthington's guide is actually not correct for my particular system (NTSC SMS II). All you need to do is lift pin 23 or... you can cut the trace on the bottom of the PCB that connects to that pin. Then you run a wire from that lifted pin 23 back to the IORQ# pad on the SMS FM board.
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