Ok - kids are in bed.. youngest had a bottle and making gurgling noises and im ready with my schematic.
I looked at the 2 pics of the drops and it looks like its wired OK so long as lug with 2 green wires links to 2 lugs over ( picture blurs out when expanded for this).
So, assuming that this is all good we need to look at where it comes to driver board.
GOR drops is solenoid 4... and is controlled through PIA4 and seeing as we only have one solenoid not working, its a good bet that this chip is OK.
Really before we go anywhere we need to ascertain that the switch for the GOR rest is reading closed... this is switch #22... its this switch that when closed allows path to ground through transistors etc.
If you put your multimeter onto CONTINUITY test and one lead to WHITE/BLUE wire and other to GREEN/ORANGE then you should read closure with all 3 drops down.. if not.. dont go any further.. this is your fault ( do this with game off).. there might be a diode across this switch.. so if it does not read closed first time then swap leads round... 2 non reads is a definate fault.
Now i cant see where this switch closure comes int the board as my copy is really crappy on this part.. but we can test the output drive.
First test to do is with game on, get your DMM and set to 20VDC put black lead to ground and test the inputs to the 7408 AND gate chip... we need to look at input at pins 1 & 2 on IC1.
You should have the same readings on both pins 1 & 2.. if not you have an input fault... the output on this is pin3 and should read the same as pins 1 & 2. If not, this chip is faulty and needs replacing.
Now turn game off again and set DMM to resistance 1K ohm and put leads across resistor R38.. should read around 560ohms. ( resistors in circuit can be a bit hit and miss if in parallel with anything but you should be good with this one)
Now test R39 ( i think.. my diag is pretty crap and im struggling to read some of it)... should read 68Ohm
Now to R40.. should be 270 Ohm.
All test good?? Ok
Move onto the pre driver.. we know the TIP102 is good as solenoid fires when tab is grounded.
Ok - game off again and set DMM to resistance X1
There are 3 legs on the predriver.
Put leads on outer 2 legs and take a reading, then swap the leads around and you should get the same reading... both should be high resistance as this is between Emitter and Collector.. there should be no connection between these two legs.
Now put leads onto middle leg and one outer and take reading.. swap leads over .. one should be high resistance and other low.
Now do this with the last outer leg and centre.. once again.. one reading high and one low.
If all the above is good then just to make sure.... turn game on ( in game mode) and put DMM to 20VDC again... put black lead to ground and put red lead to pin 5 on PIA 4... if it reads lower than 2.5V then its not enough for a logic signal and the PIA is faulty.
If we find nothing here then the output side of this is all OK and we need to look at the input... and for that i need another print off.. which means i need to buy some ink - LOL
OK - let us know the results!
