View Full Version : Dr Who Mini Playfield Opto Error

24th April 2009, 03:48 PM
Hi all,

Wondering if anyone has had experience with getting in and testing/cleaning the optos for the Time Expander mini playfield optos that register if a ball is sitting in either up-kicker.

I've had a look at the manual and also under the mini-playfield and just not sure what to tackle to get at those 2 specific optos. The manual does mention how to get at the bank of optos along the front, but that isn't what I'm after.

Any help is appreciated.



24th April 2009, 03:52 PM
Chris, when did you get your Dr Who?

If you have any probs you are welcome to come down and compare to my machine.

24th April 2009, 04:00 PM
Hey Brad,

Yeah bought it today. :) The right opto on the mini playfield is playing up...might just be grime..


24th April 2009, 07:43 PM
I managed to get at the opto causing the problem. It appears to be transmitting...maybe the IR receiver is dead??


25th April 2009, 12:51 AM
Had the same drama on my Dr Who......had to fiddle with the optos to make sure they lined up and also to make sure the targets were going in and out far enough.

25th April 2009, 09:33 AM
Ok, I'll try that. Thanks.

25th April 2009, 04:41 PM
I have found the receivers are unlikely to die - it's usually the emitters and the pic shows it working.... Chances are the solder joints on the tiny receiver pcb are cracked.


25th April 2009, 05:39 PM
Grrr... my coin door switch isn't working either! :( Keeps saying "CLOSE COIN DOOR..." Maybe it is a connector..

28th April 2009, 08:12 AM
All fixed.. BIG thanks to sparkythepinmonkey who came around on short notice for a few hrs to fix her up. I hadn't noticed that the common wire for the opto that was supposed to be daisy chained onto the opposite opto had come loose. Doh!!