ROAD SHOW FAULT: "Opto Trough Bad, Check wires, Connectors, 12 V Supply"

[iHarvest]

HI there,
Im hoping someone can help me out wit solving this one. Im pretty new to pins so a bit out of my depth.
So far i have tried different optos (both sides) from another machine and that doe not clear it.
I have also metered the 12vr 12.09 constant but 12vu is 15.44, not sure if that is relevent.
When I do a switch edge test and drop a ball all the switchs fire apart from the one for a jamed ball. I cant seem to get that one going but not sure if thats normal.
If i start the machine without any balls in, it fill it kicks them out a few times then sets to normal and it plays.

any help on this would be really apreciated, thanks

Iain.

 

[Jay Walker]

Hi, Iain,

The original message is supposedly meant to convey that all the trough optic switches are faulty, but I think that the 'Jam Ball' switch would cause a symptom like this, and you've already tried what I'd have advised as a first check. Opto switches have extra circuitry to interface with the cpu board, contained on a '7 switch pcb' under the playfield (the trough can handle up to 6 balls, depending on the particular game). It's usually near to the trough, and can be identified by a line of up to 7 large resistors for the infra-red l.e.d transmitters - original fitment ones were a blue colour, AIR. This board is the next suspect, if the trough boards are okay. The larger of its three connectors is the 12v input, ground, and the connection to the machines' switch matrix proper, the other two are for the trough boards.

With the balls out, try entering the 'Single Switch' test, and scrolling through (using +/-) to the number for 'Trough Jam'; I expect it'll show '[A] Open', meaning that it's being seen as active, i.e. the light beam appears to be interrupted.

Incidentally, what game did you borrow the two boards from? The earlier games with this 6-ball trough had more of the circuitry on the trough boards themselves. This was changed after reliability problems surfaced, in particular broken resistors (those large blue ones on the transmitter side).

 

[DRD]

Opto faults can be tricky to diagnose unfortunately, but you might also get lucky.

As said above, go into switch test t.3 to see how the opto behaves with and without balls in

If you do have a dead opto pair, these things are common failures. You might be lucky and it is just dirt, so try cleaning the opto sender and receiver (look like led bulbs) with iso propyl alcohol or anything suitable for cleaning a clear plastic lens

Switch test

Next, i would remove and reseat the connectors on the opto board, you might simply have a bad connection.

Switch test

Then remove and reseat the switch connectors on the mpu board in the backbox

Switch test

Then "short" the switch matrix wires manually to see if the mpu/ wiring is working properly up to the opto board. This cuts out the whole opto circuit.

You are then into buying a new opto pair (@myPinballs , @pinballmania etc) and soldering these in

If that does not do it, board repair. I had to do this on my tz as one of the tracks on the opto board had failed. Was a bugger to find.

Let us know how you get on

 

[iHarvest]

Thanks for the responses guys they were a great help. Trough switch was open. I checked the wires and the white/brown was not seated right in the connector. Pushed it in and it cleared the error. One last thing is there a tool to push in those wires correctly? Thanks again guys really appreciate the help. Onto the next fault now every days a school day.

 

[DRD]

For push in terminals ...



For crimp terminals ..


Speak to @pinballmania

 

[iHarvest]

nice one, thx