Sam Zehr
New member
Hi guys - having some trouble with my Pac.
The joystick is stuck right - I can go left, but not up or down. In test mode I get the constant 'Pac dying' sound. This happens even with the control panel removed and out of circuit.
Reading lawnmowerman's excellent site, I tried replacing RM8. Still happens. On the board, the resistor pack measures 1000 Ohms, except at the right input, around 343 Ohms. I figured I had a bad part - removed it. Tested a new one before installing, it was 1000 Ohms, and the same thing happened post install. I also replaced R48 while I was at it.
I'm pretty clueless on the analog stuff, so I don't know if it is even valid to measure in circuit.
I checked the ins on the 74LS367 at 8E, they are all at 5V, go to 0 if you trip the switch, except the pin 6 (right joystick) which stays around 1V, and goes to 0 when closed.
Could the '367 be the culprit? Doesn't look like anything else could be, but I suck at replacing ICs, and thought I'd doublecheck before I go through with it.
Thanks,
Sam
The joystick is stuck right - I can go left, but not up or down. In test mode I get the constant 'Pac dying' sound. This happens even with the control panel removed and out of circuit.
Reading lawnmowerman's excellent site, I tried replacing RM8. Still happens. On the board, the resistor pack measures 1000 Ohms, except at the right input, around 343 Ohms. I figured I had a bad part - removed it. Tested a new one before installing, it was 1000 Ohms, and the same thing happened post install. I also replaced R48 while I was at it.
I'm pretty clueless on the analog stuff, so I don't know if it is even valid to measure in circuit.
I checked the ins on the 74LS367 at 8E, they are all at 5V, go to 0 if you trip the switch, except the pin 6 (right joystick) which stays around 1V, and goes to 0 when closed.
Could the '367 be the culprit? Doesn't look like anything else could be, but I suck at replacing ICs, and thought I'd doublecheck before I go through with it.
Thanks,
Sam