Ok I was chasing the last fault in the Meteor - a target reset issue and managed to stuff up the machine...
Wondering if anybody has any advice on this one.
Machine was playing perfectly fine except for intermittantly dropping a few of the METEOR targets. I replaced U2 (CA3081), and then removed U2 - 74LS154 and put a socket in its place. Didn't have a new 74LS154 so just used the same (assuming I would get one today).
When I re-fitted the board, It was a little dark and I stuffed up
I managed to connect the connector for J2 on the "Regulator/Solenoid Driver Board" such that pin 1 of the connector wasn't connected, pin2 of the connector was on pin1 for the board, pin3 for the connector was on pin 2 for the board etc etc (essentially 1 pin out of place). This blew the playfield fuse (but no others). I realised and reconnected correctly & replaced the fuse. Now the machine doesn't boot properly. The displays show garbled characters, machine does try and boot, and does chime/ light the led 7 times, then makes some crappy noise and the LED either stays hard on, or just goes out. I did chuck the CRO on it, and there APPEARS to be data on the address bus from a glance (haven't actually checked for correct lines yet)
Any advice?
I seem to have all the voltaged there, although the 5 volt rail is about 4.9volts (still in tolerance for TTL from my memory)
I've looekd over the pin outs for J2 and the Stern PDF doc I have is a little blury - it looks like the problem was probably caused by pin 8 on the connector (coin lockout) being connected to pin 7 on the PCB (ground) - Im guessing this shot 42V DC down the ground line before the fuse blew (Im not sure how well the ground works on this machine and therefore whether I fried stuff
Im wondering if there is a way to test the MPU without taking it out - ie use the current power supply in the machine and go from there...
Man I've got to learn to move slower instead of rushing- major F up!