Scucci
Well-known member
Defender wasn't running, fixed power supply and decoders. Ran for a day, came back to it the next day and it was down. Found out a 7474 wasn't processing the clock right, got it back up. Came back to it a couple of days later and now I have vertical lines that change colors with the Defender logo/mutants in game.
No RAM errors, no ROM errors, good Decoders, good ribbon cable... Just really starting to reach the end of what I know with this game.
Shorted pin 23 on the decoder to flip the screen for player 2, lines were still there. People insisted it was the 165s, I ran the board on the bench and couldn't see anything obvious, socketed and replaced them all anyways. So, it's not the 165s. With the 165s socketed I tried it with all different combinations to see how the issue looked with certain ones removed... I noticed that the pixels were the lines are were black during the rug... and AWLAYS present, didn't matter which of the shift registers were removed, the lines were always there.
I SHOULD be getting some new headers in the mail tomorrow so I can check again with my decoder boards, but the lines were there with the original decoders and my replacements.
No RAM errors, no ROM errors, good Decoders, good ribbon cable... Just really starting to reach the end of what I know with this game.
Shorted pin 23 on the decoder to flip the screen for player 2, lines were still there. People insisted it was the 165s, I ran the board on the bench and couldn't see anything obvious, socketed and replaced them all anyways. So, it's not the 165s. With the 165s socketed I tried it with all different combinations to see how the issue looked with certain ones removed... I noticed that the pixels were the lines are were black during the rug... and AWLAYS present, didn't matter which of the shift registers were removed, the lines were always there.
I SHOULD be getting some new headers in the mail tomorrow so I can check again with my decoder boards, but the lines were there with the original decoders and my replacements.

