ataritoobin
Active member
MONITOR:
My After Burner Commander model worked fine, sans motors for about 30 minutes.
The monitor in this machine is a Sanwa is a PW-1545. I got it the image pretty much dialed in, aside from some squiggles at the top I assumed were cap related. Then the flyblack crapped out, making a loud clacking noise.
I replaced the flyback (TDMSH1FPU515A) and it's working again (blurry - but the B+ needs adjustment and caps need to be replaced). The sync was way off and I was unable to get it locked in with the adjustment knobs on the monitor.
I plugged another PCB into the monitor to verify it wasn't something on the monitor, and sure enough, the other PCB synced fine.
PCB:
Using my multimeter, I found the SYNC and GND lines were shorted. I traced it back to the game PCB and found that the fault was on the PCB. So I suspect when the flyback failed something shorted to the SYNC line.
I checked FLT 41 which is right before the video connector on the game PCB (a "222" not 100% sure what this part is, but a filter of some sort). I noticed the center pin on that particular one was shorted to the outer pins, which wasn't the case for the others. I removed it and jumpered the outer pins, which mimicked the behavior of the other 222s, and the SNYC line was no longer shorted to GND.
I still couldn't lock the sync in. I found the schematics on line (which looks like they were photocopied and faxed at one point - but still quite useful!) and saw SYNC input at FLT 41 comes from IC174, LS32.
Specifically, the input to FLT41 comes from pin 11 of the LS32, with input TO the LS32 on pins 13 and 12 on the LS32.
With a logic probe, I have activity on input pins 12 and 13, but stuck low output on pin 11.
I replaced and socketed the LS32 at IC174 and now have sync again. I still need to confirm what exact part FLT 41 is and replace it, but it works in the mean time.
MOTORS:
The motors would turn the machine to the RIGHT, and briefly jerk to the LEFT before reporting the LEFT movement BAD upon the bootup "MOTOR WARMING UP" test.
I went into the MOTOR TEST mode, and noticed that despite the cabinet being centered, the pot read FF and the left LIMIT SWITCH was engaged. I opened up MAME to see what the "at rest" value was (81). I pulled apart the "flared" gear that attaches to the pot in the rear of the cabinet, and adjusted the pot so it read 81. I adjusted the left limit switch so it would engage at the proper turn of the plastic piece (no idea what it's called!). I reattached the flared gear and the motors now turn properly, passed the boot-up test, and work in-game.
My After Burner Commander model worked fine, sans motors for about 30 minutes.
The monitor in this machine is a Sanwa is a PW-1545. I got it the image pretty much dialed in, aside from some squiggles at the top I assumed were cap related. Then the flyblack crapped out, making a loud clacking noise.
I replaced the flyback (TDMSH1FPU515A) and it's working again (blurry - but the B+ needs adjustment and caps need to be replaced). The sync was way off and I was unable to get it locked in with the adjustment knobs on the monitor.
I plugged another PCB into the monitor to verify it wasn't something on the monitor, and sure enough, the other PCB synced fine.
PCB:
Using my multimeter, I found the SYNC and GND lines were shorted. I traced it back to the game PCB and found that the fault was on the PCB. So I suspect when the flyback failed something shorted to the SYNC line.
I checked FLT 41 which is right before the video connector on the game PCB (a "222" not 100% sure what this part is, but a filter of some sort). I noticed the center pin on that particular one was shorted to the outer pins, which wasn't the case for the others. I removed it and jumpered the outer pins, which mimicked the behavior of the other 222s, and the SNYC line was no longer shorted to GND.
I still couldn't lock the sync in. I found the schematics on line (which looks like they were photocopied and faxed at one point - but still quite useful!) and saw SYNC input at FLT 41 comes from IC174, LS32.
Specifically, the input to FLT41 comes from pin 11 of the LS32, with input TO the LS32 on pins 13 and 12 on the LS32.
With a logic probe, I have activity on input pins 12 and 13, but stuck low output on pin 11.
I replaced and socketed the LS32 at IC174 and now have sync again. I still need to confirm what exact part FLT 41 is and replace it, but it works in the mean time.
MOTORS:
The motors would turn the machine to the RIGHT, and briefly jerk to the LEFT before reporting the LEFT movement BAD upon the bootup "MOTOR WARMING UP" test.
I went into the MOTOR TEST mode, and noticed that despite the cabinet being centered, the pot read FF and the left LIMIT SWITCH was engaged. I opened up MAME to see what the "at rest" value was (81). I pulled apart the "flared" gear that attaches to the pot in the rear of the cabinet, and adjusted the pot so it read 81. I adjusted the left limit switch so it would engage at the proper turn of the plastic piece (no idea what it's called!). I reattached the flared gear and the motors now turn properly, passed the boot-up test, and work in-game.