System 11 Flasher Help Pls - Space Station

[DRD]

Am quite new to this title and giving it some love. One of the things I loved about the System 11s was the fantastic flash bulbs (especially f14 tomcat) - but they are crap in my game!!!!

The individual flasher circuits on this game often have 3 or 4 bulbs in. I am using incandescents.

The different circuits have radically different brightness, and I have not seen this in a game before.

Does anyone know why this might be ?

4 bulb circuits ....
Right seems a bit weak
Relaunch is far too weak
Flame Flasher is absolutely pathetic

Removing 1 bulb from Flame Flasher helps, but you need to remove 2 to get the remaining ones properly bright

3 bulb circuits ....
Top Flasher is really bright, as I would expect
Left Flasher is OK, but nowhere near as good as the Top Flasher

Does anyone have any ideas what this might be pls ?

I can see that a previous owner has replaced the relevant Bridge Rectifier on the 50v circuit - I put a new one in myself.

Testing the volts to the flashers it seems to be about 38v. It is about the same on my Whirlwind and Transporter which use the same boards.

But as some flasher circuits are fine that suggests that voltage is not the problem.

Is this just a case of reflowing solder on the pins, new connector, clean bulb connectors, the bulb holders ?

Or might the power transistors that drive the flashers be failing? Or the drive transistors failing ?

Any suggestions very gratefully received

Thanks

 

[Andy_B]

I believe the number of bulbs in a flasher circuit determines the value of the related cement resistor on the interconnect board. However, this should be fixed at the factory. Do you have a replacement interconnect board from another game fitted? Are all the cement resistors connected? The wires can break over time. You can often find the resistors in the bottom of the backbox.

I'm not sure that this would give you the problem of varying brightness bulbs on the same circuit though. But I may be wrong

 

[ronsplooter]

Sounds like it could be resistance related to me so first port of call would be connectors and lamp holders along with checking the relevant solder connections as mentioned above

 

[Pudsey pinball]

Sometimes the driver transistor weakens too

 

[Spandangler]

It always had retina burning leds in when I had it mate. So never noticed.
I did a hacker repair in the aux power board when I put it up in smoke. Could it be related? That was a result of transistor locking on that board.

There’s also some nasty looking previous transistor repairs on the mpu. Wonder if any of those correspond to flashers?

 

[Andy_B]

IIRC there will be a transistor for each circuit of flashers whether there are 2, 3, 4 flashers or whatever number in that circuit
I don't believe a dodgy transistor would affect flashers differently on the same circuit. It'll be either all work or none.

 

[Jay Walker]

Space Station differs from earlier games, where the flashbulb resistors were fitted to little boards under the playfield, and later ones with them on an interconnect board below the cpu/driver board. Along with Cyclone, they're gathered together on a small pcb, inside the rear wall of the cabinet. Right where the wire harnesses can catch on them, and tricky to reach. The individual values would depend on how many lamps are used in the circuit; the more lamps are connected in parallel, the lower their combined resistance, requiring a larger resistor value to compensate. This was shown with Fire, the first game to have the bulbs in parallel - the resistors, which remained the value suited to serial connection, allowed bulbs to expire very quickly.

Eight of the flashbulb circuits are doubled onto solenoid circuits by the solenoid extender. With these the solenoid (where there is one) is a guide to the state of the drive transistor, though not the flashbulb part of the return circuit.

I didn't think that the flashbulbs were powered from the 50v rectifier, but the 25v.

 

[DRD]

Thanks for all the tips and helping to get this thing sorted.

Space Station's aux power board is a d-11813

My Banzai, Transporter and Whirly all use a d-12247. They look similar but these have more fuses for example.

I think @Jay Walker is spot on, these are 25v circuits.

I dug this out from the rear of the cab....

Flashlamp Resistor PC Board Assembly d-11814​

This has been messed about with and has been cooked at one stage. It looks like 3 have been CHANGED by previous owners

Manual Specification/ Resistor Installed/ My Multimeter reading
R1 3 ohm/ 3/ 2.9
R2 3 ohm/ 3/ 2.9
R3 3 ohm/ 3/ 3.0
R4 3 ohm/ 4/ 0.3 CHANGED
R5 3 ohm/ 3/ 3.0 CHANGED
R6 3 ohm/ NOT marked/ 3.5 CHANGED
R7 5 ohm/ 5/ 5.2

I will replace the three that have previously been changed and see if that does anything

R6 seems to be connected to the most pathetic of the circuits - the 4x Flame plus TI Flashers, so maybe I will get lucky by changing that one