Hey everyone, I’m having very similar problems with my MPU and the displays. But with different readings and not much experience, I’m lost. Any help is appreciated. This board is for a EM friend that is helping another friend out. You know how it goes!
Bally -35 jumpered for 2716 EPROMs for a Power Play
Fully Boots on test bench and machine with no displays. Has the glow on the bottom of displays. Known good displays.
Flipped U10 and U11 no change.
Changed out U14 no change.
Repinned J1 on MPU. No change.
Followed post #5 but with different readings as follows... like old school Bob, I just received a logic probe but not sure how to use it yet. Voltages taken on U20. I think pin 1 should be higher?
Pin 1- 1.44
2- .04
3- 1.38
4- .01
5- .04
6- 1.38
7- .05
8- .02
9- .05
10- 1.40
11- .14
12- 4.54
13- 4.81
14- .40
15- .02
16- 4.99
Thanks for any help.