Getting Thing’s Opto board out – and the motor and the hand…
I managed to find a tool to remove the grub screw from the interrupter assembly on the Thing optoboard and slid the assembly off of its axis. Now just the two screws holding the board to its mount….
It turns out that these two screws have an inbuilt anti-shake washer, making them near on impossible to remove with the board in situ and the playfield raised. Infact in so doing I had to remove a microswitch and lamp from the playfield bottom in order to get at the screws with a normal screwdriver. Even then it still wasn’t possible for me to remove the screws. And in so doing, I also managed to ruin the screw heads. So now I had no chance of removing this small board without removing the whole Thing motor assembly. So this I did.
Removing the motor assembly wasn’t too difficult, it being held on to the playfield by just four screws. Two of these screws were hexagonal head screws which were easily removed with my newly acquired screwdrivers. The other two screws were standard cross head screws, once again with anti-shake washers. It was in removing these that I developed the necessary technique to remove the screws, namily a jerk and turn motion. Easy.
Having removed all the screws, taking the Thing hand asssembly out of its box was also easy, being careful not to catch any wires whilst removing it (which is easily done) and having removed the plug from the opto board and having separated the cable for the Thing magnet from the cable assembly at the relevant cable connector.
With the Thing hand assmbly now removed, getting at the opto board screws was much easier, but the screws had been really damaged by my earlier attemps to remove them, so I though I might have to drill out the screws. However, on trying my newly discovered technique for removing such screws (jerk and turn), I actually managed to remove both screws even though the cross head on both screws was badly worn!
Now onto the fault finding with the optoboard….