Firepower 2 no solenoids

[robm]

I purchased a firepower 2 a while ago in non working condition (there was one coil that used to lock on but i replaced the diode and transistors.  There were a million errors and bizarre happenings all over the machine.

I just got the MPU boards back from Jomac .  He replaced heaps of stuff but was not able to fully test it - but i'm pretty confident everything on the boards is as it should be.

The game turns on, and when i do the self test everything is fine (ie: it stays 0)

Can add credits and start a game but no solenoids work (except both flippers are fine).  All targets and other switches add to the score.

I tested the solenoid power at connector 3J3, pins 6,7,8 all have about 31V (as it should)

When i test voltage at either the solenoid driver transistors or the solenoid lugs, there is no voltage present (maybe mV)

Any ideas where to continue looking.

None of the audit/adjustment buttons in the coin door work either - have not yet tested them to determine why.

[FirePower]

I'd be looking hard at the solenoid positive that runs out and daisy chains to all the solenoids. 

Your solenoid voltage looks to be present and correct as you've measured it on the power board and also the flippers work. I haven't got a schematic in front of me but I recall the flippers go through a relay on the driver board.  The solenoids have the positive looped around to each coil (the positive will have two wires to it) and the individual drive transistor for a particular solenoid switches a connection to ground.  So if none work, the common path is the positive loop wire - I'd look pretty hard at it and the playfield to head connectors that carries it.

[robm]

Ok, I have continuity from the 3 power wires from 3J3 (power driver) pin 7 to the playfield harness and pins 6 and 8 to the coin door lockout relays.  One of these looked absolutely shagged, i have read on the pinrepair site something about these.  I quickly disconnected the ground from these and powered up but it made no difference to the symptoms described above.  I guess i should bypass these and connect up the two power wires directly from each lockout coil?  I'm wondering if this also has something to do with the coin door menu switches not working?

[FirePower]

Ok, I have continuity from the 3 power wires from 3J3 (power driver) pin 7 to the playfield harness and pins 6 and 8 to the coin door lockout relays.  One of these looked absolutely shagged, i have read on the pinrepair site something about these.  I quickly disconnected the ground from these and powered up but it made no difference to the symptoms described above.  I guess i should bypass these and connect up the two power wires directly from each lockout coil?  I'm wondering if this also has something to do with the coin door menu switches not working?

No need to have the coin lockout coils in circuit - just remove them and insulate the wires if you wish, but maintain any loopings in place.   Certainly do not connect up the wires - that will blow a fuse instantly.  If I understand what you're saying correctly, it's not likely the lockouts are causing you problems. Generally a coil will fail in one of two ways - open circuit so it does not work and does no harm. or short circuit where it will blow a fuse.  You have neither of these cases.

I'd examine the solenoid bridge and find the negative terminal, then measure the voltage from bridge negative to any coil terminal which has two wires on it - this will be a positive. You should see 28V, but my guess is you are not seeing anything. Follow the wires from the terminal with two wires back to the power supply board, lack of continuity here is likely to be the problem.
 

[robm]

Thanks Firepower - spot on the money!!

One of the connectors at 3J3 in the power supply board was dodgy - when i probed it hard enough with the multimeter it would get a reading, but i noticed it sometimes fluctuated.

New plug and all sweet.

Thanks