I have a Doctor Who Pinball and my optos are playing up. I was sent another set by the guy that I purchased it off but they don't seem to work.
What I've done is the following.
The original optos that came with the machine gave two errors out of the five on startup. Running the switch test I found that two optos did not respond.
I pulled the mini playfield to bits and checked them with a digital camera. Two were dead.
The second opto set arrived and I dismounted the mini playfield and stuck them in. None of the five worked???
So I dismounted the playfield again and checked them with a digital camera. They seemed to have a faint light.
Whats the best way to test them? Do I need to have the entire mini playfield mounted? Can I just plug them in a see with a digital camera if they leds light up?