Centipede not pushing power to the monitor.

TheDrewster

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This Centipede has me confused. The game plays blind, everything works but the G07 never fired up. First thing I did was swap monitors, I put in a k7000 and it didn't fire up either. At that point I figured it was something wrong with the AC unit. So not wanting to mess with trying to poke and prod with the AC assembly, I bought a complete working one, put the G07 back in, and STILL nothing. What am I missing here? I'm going to check continuity of the harness between the monitors power plug and the AC unit later, but is there anything else I can check?
 
First thing to check with either power supply installed is if you are getting AC at the monitor plug (after unplugging it from the monitor). If not, check the 15-pin power plug on the wiring harness where it plugs into the brick and see if any of the pins have been pushed out or are otherwise not making contact. I would suspect the plug on harness since you said both bricks are doing the same thing.
 
you swapped monitors, and bought a replacement transformer assembly without metering the voltage on your a/c plug first?
 
you swapped monitors, and bought a replacement transformer assembly without metering the voltage on your a/c plug first?

Yeah, I know. I have a tendency to accidentally skip the simple shit sometimes.

Will check the plugs and report back.
 
Checked harness continuity and everything was good. I did, however, discover something interesting. Both monitors that I used have now developed some sort of short between the two AC connector pins. The original G07 is shorted and I know for a fact one of the monitors I used (k7000) was working before putting it in this machine. What do I need to check to make sure that I don't possibly toast a third monitor?
 
Sure enough, there is a short in the power brick with at that connector. Bridge rectifier?
 
Found out something else. If I have my test leads in the monitor connector with the 15-pin connector plugged in, it sees a short. Unplugged, sees open line, no short. But if I probe the two pins for the monitor power in the power brick directly, there's no short. It's only shorted when that connector is plugged in it seems.
 
by a "short" i assume you mean continuity. there should be continuity between the two wires back through the transformer. it wouldnt work if there wasnt.
 
Continuity between the two pins of the power connector? That seems strange... None of my other monitors show continuity between the two wires in that power connector.
 
If there was no continuity, then it would be an open circuit and would not work. Unless I am not understanding what you are saying.
 
Just for shits I went out to my paperboy, unplugged the power connector feeding the monitor and metered both wires. It shows a resistance of 1.3 ohm.
 
Just for shits I went out to my paperboy, unplugged the power connector feeding the monitor and metered both wires. It shows a resistance of 1.3 ohm.



I get a resistance of .6 or lower if my memory serves me correctly. Low enough to make my multimeter beep and think it's a "short." When I meter the connectors on all my other chassis and monitors that I haven't used in this game, it sees continuity but reads the resistance without the "short" beep going off. I want to say I remember 1.3ish on my other chassis as well. I'll have to recheck.

I'll whip up a quick video later tonight and post it.
 
our Centipede had a similar issue, but I think the entire machine wouldn't turn on. you'll have to pull the power block out and check all the wiring underneath. AC runs to a couple different plugs for instance. I don't remember what it looks like, but something was wrong on ours and I eventually fixed it.
 
check for AC voltage at that two pin connector. The "short" you are seeing is the resistance across the secondary winding of the isolation transformer (which BTW is just a long piece of wire wrapped around an iron core).

look at the attached pic: according to the wiring diagram the monitor gets its power from pins 10 and 15 (60VAC+60VAC=120VAC). Pins 12 are 13 and jumpered to complete the connections between the transformer windings. If your not getting 120VAC between pins 10 and 15, WITH THE CONNECTOR PLUGGED IN, then you either have a bad transformer (which I think you ruled out) or a problem with the harness (make sure that jumper is there).

BTW, there is no fuse in regards to the monitors ISO other then the main fuse. If that fuse were blown the cabinet would be dead.

The rectifier is only for the +10.3/+5VDC supply.
 

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I wish I can say I figured it out, but now all the sudden it works perfectly fine. I didn't change anything or do anything different from last night but I fired it up and it wants to make a fool out of me. Thanks guys!
 
make sure the pins inside the connector for the monitor are secure. maybe they popped out or werent making good connection? glad it's working now.
 
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