new moon patrol troubleshooting thread.

vintagegamer

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The last few times i have tried to power up my moon patrol, i get a loud hum in the speakers and 'led 1' on the ps board doesn't lite up. Game also does not boot. If i unplug the edge connector from the pcb and turn on the game, all 3 led's lite up on the ps board. I now have 2 separate mp boardsets and the same happens with either set in the game. I replaced the 15-pin connector that goes to the ps board and the ps board was rebuilt by yellow dog. Any ideas before i pull the trigger on a switcher? :(
 
PS i have checked the voltages on the pins in the edge connector for the pcb and they are fine, at 4.9 and 12.0-2. It happens even with the monitor AC and video wires disconnected so I'm guessing edge connector or something thereabouts. If any locals would be up for taking a look i could sure use some help.
 
The last few times i have tried to power up my moon patrol, i get a loud hum in the speakers and 'led 1' on the ps board doesn't lite up. Game also does not boot. If i unplug the edge connector from the pcb and turn on the game, all 3 led's lite up on the ps board. I now have 2 separate mp boardsets and the same happens with either set in the game. I replaced the 15-pin connector that goes to the ps board and the ps board was rebuilt by yellow dog. Any ideas before i pull the trigger on a switcher? :(

If you have two sets of boards, you could try swapping boards between the sets to try and narrow it down.
 
PS i have checked the voltages on the pins in the edge connector for the pcb and they are fine, at 4.9 and 12.0-2. It happens even with the monitor AC and video wires disconnected so I'm guessing edge connector or something thereabouts. If any locals would be up for taking a look i could sure use some help.

Did you check the voltages at the Chips? Pick a couple of IC's farthest from the edge connector and test them.

Testing them at the connector can be misleading. It should be tested on the PCB itself to get a more accurate reading of voltage used by the PCB. If you get 4.9 at the edge connector and are only getting say 4.4 at the other end of the board, you then need to find out why. If you're getting 4.9 at the edge connector and 4.8 at the other end of the board, you're probably fine.
 
Did you check the voltages at the Chips? Pick a couple of IC's farthest from the edge connector and test them.

Testing them at the connector can be misleading. It should be tested on the PCB itself to get a more accurate reading of voltage used by the PCB. If you get 4.9 at the edge connector and are only getting say 4.4 at the other end of the board, you then need to find out why. If you're getting 4.9 at the edge connector and 4.8 at the other end of the board, you're probably fine.

I will try. This is just damned insane.
 
Well i have an update. I found the 7amp slo blo at f5 was black in the middle. The fuse tests as ok with my DMM but i don't believe it.

I also have no ac going to the monitor so i am thinking maybe my transformer is dying?
 
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Well i have an update. I found the 7amp slo blo at f5 was black in the middle. The fuse tests as ok with my DMM but i don't believe it.

I also have no ac going to the monitor so i am thinking maybe my transformer is dying?

Should be easy enough to test. Check the voltage at the monitor plug and see what you're getting. If you're not getting anything, follow it back to the ISO and check the inputs to the ISO. If you are getting 120V but nothing out, then you have a bad ISO. If you're not getting anything in to the ISO, then your problem is further down the line.
 
Don't swap boards and chips around, that's a working set....you've got power supply issues, or edge connector problem. Hopefully someone out there can give you a hand.....
 
Make sure you pull the fuse out to test it. Testing it in circuit will give you a false positive.

-Mike
 
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