I bought two or three sets of unknown/untested/bad boards sometime last year. I have recently started going through them to determine the severity of their problem(s). (This is taking a surprisingly long amount of time due to the time it takes to create a JAMMA adapters for each unique interface! :/ )
Anyhoo, I came across a complete, intact Kangaroo board last weekend! After creating a minimal adapter (Power and Video), the board came right up! I tried its self-test and it passed. After watching the attract mode for a little bit (~30 seconds), the game started to show some visual artifacts on the RHS of the screen. They were horizontal blurbs that looked like multicolor static. However, each of the blurbs, while in a random vertical location, were identical.
This appeared to be a thermal issue. The problem went away when I shut the board off for a little while and then came back after a short time. Oddly enough, freeze-spray did not have an effect on anything!
I first thought of a RAM or addressing problem, so I broke out the Fluke 9010 with the Z-80 Pod and ran a RAM test. RAM test passed! BUS test will not run on this board, I do not know why, but I remember reading/hearing that is certain hardware out there that the Fluke cannot work correctly with due to how it loads the bus on the board. Oh, wellâ€¦
I tried writing to some of the video locations (special processor commands) and got some visual indicators but not the garbage I was seeing before. I then ran the board under the Fluke and noticed that I was not getting any garbage on the screen! I let it run for a good 15 minutes and then started to think that the original CPU might have been wonky. I replaced it and let the game run and STILL no garbage! :^O
Pressing on the CPU in various ways gave me a flicker on the screen, so I think that the CPU’s socket could use a replacement. I will wait for my desoldering unit to arrive before I do this, desoldering 40 pins with just an iron, some braid and a sold-a-pulit is a real pain in the ass!
Other than that, I have a completely working Kangaroo board! Woohoo!
Lesson learned: first thing you do is reseat all connectors and chips when starting a repair effort. I still have to learn that, it seems!
Solution: Replaced bad CPU Socket (wel, at least, I will soon…)