HI all - I hope somebody can help with my issues - new purchase, as a project but this is my 1st Gottlieb.

3 Issues that I think are probably all related:

1. Half of my coils including the left flipper are receiving 12v. the other half 60v?? I have checked the driver board input and all items are receiving 50+ volts. but testing the mosfets with a voltmeter - half only show 12v? any ideas? is this a mosfet issue or something else? please not a new driver board...
2. I can't get into the diagnostic mode - I can play a game no issue but the left flipper is doing nothing in system setup - is this because it does not have enough volts? I reckon probably?
3. I had had to remove a dead coil - could this be the reason for all of the above? some other coils have 50v but are not triggering - is this because the coil is removed? They are not all on the same circuit according to the schematic.

So please if anybody has any experience and can help - greatly appreciated..

Mike

Further investigation hopefully this can help locate an issue...

The Q cabinet relay - 1 switch is full power, one is 12v.
the transformer appears to be providing the right power

so somewhere between the transformer and the 1 relay, half the coils are losing all power?

Ok thanks guys. Will await the new coil and see how it looks - will probably have to follow the cable.loke you say.
My guess is another blown coil or diode...

Will check the transistors after leaving the machine on - good call..
Today I removed a fuse from another coil that was blowing it's fuse and the volts jumped back to 48.....and I could enter diagnostic s no issue.

Agree it is probably a bad solder - one of the other coils is throwing a fuse whenever i add one - must be something in the chain.

I will slowly go through and re-solder all coils and see if this fixes it.

If any MOSFETs are hot - I have some new ones on order and will swap. There are already a few new ones added - I think it was over fused and this blew them- machine was in circuit in Greece! Lost of interesting "fixes" to replace.

Will check back in when the new could is added and I have re-soldered everything..

OK. This machine has issues....
Fixed the voltage - tblown MOSFET was causing it.

I had 1 coil locked on - 3 issues.... Coil blown, MOSFET blown, opto dirty so when all fixed - the coil stayed on.. that took 3 days.

I think the driver board has seen better days - multiple repairs.
I have 3 coils not working and I think all is due to the board.

I fixed 2 I think but the board was over fused and when the 3rd was trigerred i blew 3 MOSFETs - somebody had put a wire behind the fuse...

So - long story. But question..

I have 3 coils, full voltage now - they aren't activating - can I presume this is a driver board issue?
I am seriously considering getting a rottendog replacement but am worried it might blow.

Am going to check the 3 coils resistance to make sure nothing is broken and then rework the MOSFETs - they are not registering as broken with a multimeter but I think the soldering is dodgy.

OK, all repaired and new coils, awaiting a new driver board before I replace the fuse again...
will do the grounding wire fix this week as well.

WOW - amazing what can happen when you throw money at a machine!!!

new Rottendog driver board arrived today. Plugged it in and everything is working. I am pretty sure the old board had screwed grounding problems due to terrible repairs from the previous owner - or actually, probably the guy repairing it when it was on circuit.

total repairs just to get it working was:
4 out of 5 Opto's were mis-aligned and needed fixing
1 broken opto - the final of 5...
5 new coils - 4 were dead, 1, I killed - not bad for a game with only 11 coils to start with...
full fuse swap
supplemental driver board, 1 new mosfet
2 switches re-soldered
New Driver board...

Now, to get is playing well I have also:
flippers rebuilt
full Led swapout
full cleanup - I thought the plastic ramp was cloudy brown from factory!!!
New cliffy protector

I have 2 broken plastics that I will glue and then protect with Mylar to hold it together.

PLayfield is not good - the Mylar has had it and between the flippers the paint has been worn through. I would need to take the mylar off and clear coat to make it look remotely good - but this is a machine to be played on so will probably leave that for another time - or for another more dedicated repair person - I really enjoy getting em working but have no idea how to clear coat or repaint a play field...

pictures coming soon.

OK - game is now playing...

all appears to be perfect apart from shoot the deez....

OPTO's are registering absolute fine.
ship is turning but when a ball is caught - nothing happens....

Can this possible be because I put the Opto holders in the wrong way round - Opto 1 where Opt 2 should be?

Does anybody know how the machine recognises the captured ball? it is when the Opto' register one after the other and then nothing?

Anybody have an Idea?

It was the opto's the wrong way round...

Game is finally playing.
Now I need to dial everything in and good to go. Played a couple of rounds - fast game..

I thought Twilight zone was hard to get working right but man, that was easy compared to this....