Normally the opto transmitter shines bright red LED light into the opto receiver. Through some transistors on the opto amplifier board (and logic gates) the CPU "sees" this as an open switch. If the transmitter LED fails (or the light is blocked by the ball), the receiver changes voltage and the switch is detected as closed.
The opto went on / off during a switch test when the ring was banged or the glass slid back in place sharply. Looking at the opto amplifier board mounted to the right of the backboard there was a 2-pin connector that had been bent right over, probably the transmitter opto to the ring. Turned off game, bent the pins up straight and plugged back in connector. Switch test showed the "ring made" working only when it should again (stick finger in the ring).
At least that fault was fairly easy to diagnose and fix.
20th Aug 2010: Still working.
ReplyDeleteI just got a brand new LOTR LE pinball machine this week, and was having the exact same problem. The ring was never detecting the ball, and the switch test was indicating the opto switch always on.
ReplyDeleteI searched the web for info and found this post. I checked the connections in the back, and nothing was bent, but for good measure I unplugged them and plugged them back in again. And this fixed the problem!
I must say the game is even more fun when the ring modes work! I'll be bookmarking this blog, as it looks like a great resource for new LOTR owners like myself. Thanks for creating it!
Congratulations on your purchase of an excellent game! I couldn't resist the chance to own one as my first NIB pinball game.
ReplyDeleteIt hasn't been without challenges and some problems, as documented here. However LOTR is Stern's best effort to date and has become an instant classic. I'm glad I bought it, even at the price we pay for new Sterns in the UK.
Good to hear these pages are of use to someone else. Best Wishes and Happy flipping!