Track and field bad sync + other issues

[Shinydaz]

I picked up another faulty track and field board which wouldn't sync.
A quick inspection revealed a couple of issues:
Missing caps and dry joints on the power connections:

After replacing the caps and fixing the dry joints I fired it up.

After a bit of research I decided to start at the 74ls244 @ C1. Hooked up the probe and pin 9 was stuck low. So I pulled it out, checked it on the mini pro, to confirm it was bad.

Replacing it fixed the sync issue but revealed more issues.

This point seamed a good time to try the test rom.

Replaced bad 2114 @ 11B

This is as far as I had time to go tonight. So we have a rom/socket problem @ A3 and bad sram at 6A, I'll be replacing this stuff tomorrow night.

This test rom is great from shoestring.Shinydaz2017-03-02 15:22:20

 

[Shinydaz]

So I Swapped out the rom at A3.
I still had sprite problems.

So I probed the 74LS243 @ 15A and there was no output at pin 9. Pulled it out and ran it through the minipro.

Pulled one off a donor board and voila.

I think I got lucky fixing this, but I'm learning everyday. Maybe the next step is to buy an oscilloscope.Shinydaz2017-03-03 04:04:04