Flipper problems on pinball

[tk1959]

I have a old Bally Skate Ball pinball game. The original problem was when you hit both flippers at the same time the game shuts down. I have been living with that. Today the left flipper quit working. I found the tracer on the Solenoid driver board between Cap c17 and j2 pin 5 lifted. I jumped it out with a wire. when I plugged it back in resistor r 16 went up in smoke. Anybody have suggestions other then changing the cap and resistor? I am new to all this.  Thanks in advance

[Q*Bert_OP]

have a pro do it

[ChadTower]

First thing, don't jump stuff on the circuit boards if you're not sure what the cause of the problem is.  That part burned up for a reason and you just gave the overload a new path to follow to do even more damage.

First guess is a bad solenoid in the flipper circuit.  Test those out for reasonable resistances to see if one is shorted out and drawing enough power to shut the game down (the reset you saw).  If one is that bad then it's going to have a very different pair of resistances than the others of the same type. 

Does that pin have diodes on the flipper coils?  If so, check those too, making sure to lift one leg when you do it to get a proper test on it.

[tk1959]

thanks chad, I changed all the flipper coils about a month ago, and yes they do have the diodes. I will check all the coils again

[ChadTower]

I can't remember, would this pin have driver transistors for the flipper coils?

Also have a look at the EOS switches to make sure they are clean and closing/opening properly.  A misadjusted EOS switch could cause that too, where the high current draw never leaves the circuit once the flipper is at full extension and eventually burns up at the connector pin where you saw it.

And now you're going to have to replace both the male header and the female pin in J2.  You should probably do the whole header and connector while you're bothering but not until after you solve the issue (otherwise you'll just fry it again in the process).

[D_Zoot]

This vintage pin wouldn't have transistor driven flippers.

Connector J2 pin 5 is the knocker circuit,  C17 and R16 are part of the driver circuit for the knocker (along with transistor Q3)

This is an unusual problem, the damage on the driver board shouldn't have anything to do with the flippers directly.  Did it blow any fuses?

I'm wondering if you have a short somewhere.

D

[tk1959]

Have disconnected the jumper wire I put on the board and re installed it. Everything is back to where I started. I still have no left flippers but everything else seems to be okay. I don't want to sound real dumb but what is the knocker. All the thumpers and solenoids seem to be firing. Is the knocker the solenoid that fires when you win a free game?
If that is it I will remove it. it is only in my basement for my enjoyment

[ChadTower]

Is the knocker the solenoid that fires when you win a free game?
If that is it I will remove it. it is only in my basement for my enjoyment

Yes.  It would be either in the head or down inside the cabinet.

[extremepong]

I'm no expert. on any of this but I wonder about the following:  Suppose the suspect flipper coil was replaced by a small relay and that relay was then used to power the solenoid coil (using a separate  power supply). This workaround might either get it working or have diagnostic value if it fails.

[cdbrown]

No idea as well but - did you check the flipper button to make sure the leafswitch is working (assuming it's a leafswitch).  If it's not registering the button being pressed, then it ain't going to work.

[tk1959]

Thanks for the suggestions, I found The knocker coil was shorted so I have disconnected it. I am in the process of repairing the damage on the solinoid driver board. As far as the flippers are concerned I have checked continuity back to the driver board. as of now it looks like it might be in the relay on the board. I can't see the back set of contacts because of a heat sink next to it. I was going to take it off the board and check it out when I do the board repair.