Another update.
The game is now in the house! Lined up beside the tz and
afm. I've been trouble shooting.
First issue was a flaky trough opto. Opto 5 was failing to register at all. First thought was the transmitter so off the trough boards came to check them. Transmitter successfully operated other receivers so I discounted that. I then swapped out the reciever. No change. Swapping a known good reciever showed no improvement so after checking the wiring I was onto the opto board. Jumpering the input connector worked for all inputs apart from trough 4. So I suspected the lm339 comparator. First job was to remove the old one. I'm not blessed with a de soldering station so I employed a slightly unorthodox method. Tool a dremel with a cut off wheel and carefully cut the chip free from the legs
I then removed each pin in turn. Used my solder sucker to clear the holes
Then soldered in a socket and installed a new lm339
Cleaned off the flux and reinstalled. All worked nicely.
Next up the trunk opto board. Opto 55 registering flaky. When moving the trunk it registers as open for a split second and then closed immediately. I saw that the plastic hood was broken so I popped a new hood on. No improvement. I ran out of time so next step is a new u opto. Fingers crossed! I've not checked which lm339 controls this so I may end up replacing the other one!
Fingers crossed ill get some more time to tinker tomorrow.
On another plus note the rom from Paul arrived. I had sent him a hacked version of 1.4h (as originally it needed a special u22). The hack allows any wpc-s rom to work with any working u22, rather than the game specific one. Worked first time. I can now report that my tiger saw saws properly!! The only point I've not fully tested is the amount the saw spins. I had used a 12v geared motor to limit the speed to 120rpm. I didnt want it spinning so fast it wasnt visible. I'm hoping that it will spin enough to look right!! If I can upload a video ill get one up soon.
Next issue was the spirit ring. As supplied it has 2 spacer washers between the bracket and the ring to raise it up. Without the washers the ball hits the magnet and stops. I carefully trimmed the cardboard former to clear it. Looks much nicer without the bodge washers and seems to work nicely. Proper play testing will reveal all!!
One pitfall I fell into was with the trapdoor. I had forgotten that the popper had a spring each side of the coil. The idea is that it holds the popper half way up until a ball hits it. Then the weight of the ball pushes it all the way down and triggers the switch. Bit of head scratching and the penny dropped!! It now only registers a ball when there is one on it!!
One quick question for Tom owners. My bottom captive ball switch registers as closed when a ball is sat on it. The single switch test suggests that it shouldn't be like this and should be normally open. Can someone check whether this is the case for me?