cenatur2
New member
Hi guys,
I have a problem with my TKG-4 2-board DK PCB.
When playing, parts of the screen start to jump a tiny little bit.
It is most obvious on the second level, where the right third of the blue
platforms move up and down corresponding with DK moving his arm.
Please have a look at the video:
https://www.youtube.com/watch?v=fR1BgH3rWDs
It is more or less present in all my videos:
https://www.youtube.com/channel/UCGjOB8gD5mug6uWRa6CymuA
I am pretty sure the Sanyo EZ20 is ok, it has been recapped and I have
connected another game to it that runs without problems. So, this only
leaves PCB and power supply.
What I have already tried:
- completely recapped the PP-7B power supply
- completely recapped the PCB
- replaced the VPOS and HPOS pot with resistors to take these out of the equation
- adjusted +5 and -5 voltages to 5.12 and -5.3 V (ECL logic need -5.2V)
- tried a different Z80A CPU
- cleaned all socketed chip legs
- changed all 2SC1815 transistors on the PCB (because I have a faint siren noise, did not go away although I changed Q2, Q4 and Q6)
I am really out of ideas. I have read and watched all repair info I could find, but have not
seen this kind of problem.
When looking at the video board, the 3 74LS163 at 1L 1M 1N have quite
dark legs and they run really hot to the touch. Is that normal?
Also, I took of the shield box on the video board, and the coil at L1 looks crappy (by design?).
But I have seen this somewhere on another board before, so should be ok.
Really thankful for any input!
Sebastian
I have a problem with my TKG-4 2-board DK PCB.
When playing, parts of the screen start to jump a tiny little bit.
It is most obvious on the second level, where the right third of the blue
platforms move up and down corresponding with DK moving his arm.
Please have a look at the video:
https://www.youtube.com/watch?v=fR1BgH3rWDs
It is more or less present in all my videos:
https://www.youtube.com/channel/UCGjOB8gD5mug6uWRa6CymuA
I am pretty sure the Sanyo EZ20 is ok, it has been recapped and I have
connected another game to it that runs without problems. So, this only
leaves PCB and power supply.
What I have already tried:
- completely recapped the PP-7B power supply
- completely recapped the PCB
- replaced the VPOS and HPOS pot with resistors to take these out of the equation
- adjusted +5 and -5 voltages to 5.12 and -5.3 V (ECL logic need -5.2V)
- tried a different Z80A CPU
- cleaned all socketed chip legs
- changed all 2SC1815 transistors on the PCB (because I have a faint siren noise, did not go away although I changed Q2, Q4 and Q6)
I am really out of ideas. I have read and watched all repair info I could find, but have not
seen this kind of problem.
When looking at the video board, the 3 74LS163 at 1L 1M 1N have quite
dark legs and they run really hot to the touch. Is that normal?
Also, I took of the shield box on the video board, and the coil at L1 looks crappy (by design?).
But I have seen this somewhere on another board before, so should be ok.
Really thankful for any input!
Sebastian



