Twilight zone clock, rottendog board

[DRD]

My tz clock only works periodically. And may indeed pack up mid game. The previous owner put a rottendog board in it

I have dismantled it to check the 8 optos that are used to register the time

All 8 seem to work fine. But I did notice that this board (which has 4 led lights) gets very hot very quickly. The resistors in it rapidly become hot enough to burn your skin

Is this normal with opto boards pls, or might this indicate a problem with this rottendog board ?

Thanks

 

[elrikos]

I've never had a rottendog version of this, but looking at it its basically the same as the original board except uses LEDs for the gi and therefore current limiting resistors. There are also current limiting resistors for the emitter part of the optos. They're going to get toasty so I would say no fault. The optos in the clock are special spec and can go flaky quite easily.
I'd be tempted to rebuild the clock and make sure that the optos are nice and clean. Also that the minute hand is reliably breaking the opto beam (you can wrap a small piece of tape around the arm to extend it slightly). Use the tests to see if you have a failing opto. It will usually display by flickering on and off. You can then just replace that one. I'd imagine that Andy at pinballmania sells them.
Alternatively, look at ingo kramers board (german pinball modular). It's a significantly better design using standard components. I've had one for a couple of years and it's been faultless.

 

[DRD]

Thanks for this.

The damned clock is so unreliable, I wish it had never seen the light of day. I did find a fault on the board under the playfield that controls the motor. It had a dry joint.

I thought i had cracked it, but i am still getting an occasional miss with the optos. This is caused by play in the mechanism so the minute hand can move away from the clock face minute optos. The previous owner had put insulation tape on to help, but that smeared gunk around the clock face

I have already replaced the clock gears with new ones, but there is still play in it

I think i need to find something non gunky that will extend the actuator on the minute hand

If i can't nail this, i will buy one of the german boards

 

[elrikos]

I know one part of ingos website shows the height of his minute optos as higher than a "competitors" ones. I guess the competitor is rottendog as I'm not aware of any other boards. Is it possible to desolder the minute optos and move them 1mm or so further out? That may solve it, if there's enough component lead length

 

[Adrian Hufton]

When I first got my TZ (with Rottendog board) mine was failing mid game, it was registering in test so I took it apart and cleaned the optos, never missed a beat since.

 

[Wizcat]

The other thing to check is that the clock housing is tightened up nicely. I had very similar issues with mine, and it was solved by tightening everything up, to remove any looseness in the clock arms and housing in general.

 

[DRD]

Given optos a good clean. Clock is as tight as it sensibly can be.. This clock has new gears, new rottendog board, new front lens and a new clock housing. But there is still about 1mm of play (in and out of the clock) on the minute hand.

When i run the clock test in slow, it beeps as the minute hand passes every quarter opto. And the dmd indicates this with a cross in the relevant quarter hour box

But when i run it on a fast test, it again beeps on every quarter but sometimes no x appears in the relevant quarter hour box

Could i ask if this is normal (ie the fast test is so fast the dmd does not always register the x in the quarter box), or whether it is indicative of a possible fault

Sorry to trouble the tz fraternity, but this clock is driving me (and presumably the previous owner too)
mad

Thanks

 

[Moonraker]

But when i run it on a fast test, it again beeps on every quarter but sometimes no x appears in the relevant quarter hour box

Could i ask if this is normal (ie the fast test is so fast the dmd does not always register the x in the quarter box), or whether it is indicative of a possible fault

I would say that the machine beeps when there should be an X in the quarter box and that it is not always registering an X is indeed your fault. This may be the opto, the opto interrupter (clock arm) or a broken wire.