I got this when I first starting learning to fix boards. When I first looked at it, I was poking around with the probe not really knowing what I was doing, so I put it back in the pile.
I'm slowly learning more each week, so I thought I'd drag it out again. The problem is missing sprites, the test rom is showing a j9 ram error on the lower board. Now I've learnt this doesn't necessarily mean the ram is faulty.
So I started poking around and I stumbled on some select pins with no input. All select pins (pin 2) on these ls153's was dead
After following it back through a few chips, I found the dead signal was from this ls04 (pin 12).
I pulled it out and tested it.
This restored the sprites but I still have a sprite issue to sort out.
The test rom now states no issues. It's heading in the right direction at least.Shinydaz2017-06-21 05:36:49
I'm slowly learning more each week, so I thought I'd drag it out again. The problem is missing sprites, the test rom is showing a j9 ram error on the lower board. Now I've learnt this doesn't necessarily mean the ram is faulty.
So I started poking around and I stumbled on some select pins with no input. All select pins (pin 2) on these ls153's was dead
After following it back through a few chips, I found the dead signal was from this ls04 (pin 12).
I pulled it out and tested it.
This restored the sprites but I still have a sprite issue to sort out.
The test rom now states no issues. It's heading in the right direction at least.Shinydaz2017-06-21 05:36:49
