I have this board from a pinbot on the bench with GND, 5V and 12V. I've burned a Leon test rom for it and have it installed at U26.

I have all the PIAs pulled at this point except U38 (not socketed).

There is some previous rework U16, U28, U39, U43 (555), U55 all socketed. Work looks decent (although nasty flux remains). I have pulled and tested these chips with a little chip tester. The socket at U20 looks factory and the 7408 tests fine.

The 7 segment LED does not light at all. I get a little flash (very dim) out of it when I turn power off. The LED used for Leon's test burns constantly.

Blanking stays low, Reset starts low and quickly goes high. The clock signal measured at the processor is 3.99 mhz

The board has had the battery pack removed and while kind of grungy doesn't look battery damaged.

If anybody could give me some hints on what to try next I would appreciate it.

Thanks!

Here's come pics. I found a solder blob between U29 and U38. If I had to guess I think a previous owner dropped an iron there. Cleaned that up but no change

2016-09-28 09.48.09 (resized).jpg2016-09-28 09.48.26 (resized).jpg2016-09-28 09.48.20 (resized).jpg2016-09-28 09.48.14 (resized).jpg2016-09-28 09.48.39 (resized).jpg2016-09-28 09.48.46 (resized).jpg2016-09-28 09.48.49 (resized).jpg2016-09-28 09.48.43 (resized).jpg

UPDATE: moved the test rom to U27 and the LED is blinking. 7 segment still blank. I'll repopulate the PIAs and test it out.

Any suggestions on the LED not working? UPDATE: Put the PIAs in and the LED works as well

Thanks