Game booted to garbage, no sync.
Probed Z80, reset stuck low, clock ok.
Disabled watchdog and z80 ran but still no sync...
read an amidar repair log with same symptoms, fix was a bad 161 counter.
probed counters found fujitsu 161 at 7L with two outputs stuck high.
piggybacked my last spare 161 and the game worked, swapped it out and all is well
pays to do a quick google sometimes
Probed Z80, reset stuck low, clock ok.
Disabled watchdog and z80 ran but still no sync...
read an amidar repair log with same symptoms, fix was a bad 161 counter.
probed counters found fujitsu 161 at 7L with two outputs stuck high.
piggybacked my last spare 161 and the game worked, swapped it out and all is well
pays to do a quick google sometimes