Coils still burning up? Here is a process for System 1 games (works with System 80 on with minor modifications).
You will now need a voltmeter and a couple of jumper wires.
1) Unplug the game.
2) One way to see if you can find the problem is to first remove the 28VDC solenoid fuse before doing the following tests (lets not burn up any more coils).
3) Turn voltmeter off(why waste the battery?) Connect one jumper wire to the copper ground plate on the transformer board under the cabinet. Connect the other end to the negative of the filter cap on the power supply and set the voltmeter to the 2VDC range.
4) Now turn the game on and leave it on for an hour or three.
5) (hour or so later) Now turn voltmeter on - the voltage should be pretty much 0.00VDC, with a max of 0.1VDC (less is better). Turn the meter to AC voltage, again should be virtually zero volts AC. If the DC voltage is over 0.01 find the problem! repeat steps 3 - 5, going on to 6 when 5 is OK.
6) OK, now the power supply common/ground voltage relative to the cabinet ground is essentially 0VDC - check the voltage from the driver board logic common/ground to the cabinet ground (that copper strip). This too should be virtually 0VDC - under 0.01 if ground wires added.
7) OK, turn game off and replace solenoid fuse. Put meter (turn on and set to 2VDC range) lead back to power supply capacitor common/ground (you did leave the other lead connected to the copper ground strip - right?). Watch meter when you turn on the power. Should be same results as step 5. If not turn game off and fix ground connection problem.
8) If step 7 is OK, then move meter lead to drive board common and compare to reading in step 6. If OK, then feel temperature of the driver transistors with your fingers (28VDC, should be fine if fingers not damp otherwise mild tingle) - should be at room temperature. Check with finger again in a minute or two. These should NEVER be much more than room temperature when the game is on but idle (attract mode only). If hot or warmer than neighbours turn game off and let us know - there are a few other tests you can do with a voltmeter and the solenoid fuse removed that will pinpoint the problem. |