Donkey Kong 2-board PCB - unstable picture

cenatur2

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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
 

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Also, I took of the shield box on the video board, and the coil at L1 looks crappy (by design?).

I know this thread is a year old, but there's not a single google hit, nor is this part #
listed in any 1000+ pdf schematics of nintendo for TKG4 pcb's. If L1 is an inductor/coil,
wtf is the part # and how many uH (micro-henries) is it?

thank you!
 
You may want to adjust the 2 50k pots on the PCB itself.... sometimes the simplest answer is correct once in a while.
 
You may want to adjust the 2 50k pots on the PCB itself.... sometimes the simplest answer is correct once in a while.

Replaced BOTH 50k pots with spanking new OG ones...

WHAT IN THE HOLY FUCK IS THE GD VALUE OF THAT MOTHERFUCKING L1 INDUCTOR?

that's all i want to know. it's that simple. thank you.
 
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

There is no solder on the lower leg of the crystal
 
Thanks for the info on the 50K pots. Where are those located?

@thegleek I wish I knew the value of the L1 so I could help. Just started this hobby so I haven't a clue. I ordered an official manual from a klover will it show it in there?
 
Thanks for the info on the 50K pots. Where are those located?

@thegleek I wish I knew the value of the L1 so I could help. Just started this hobby so I haven't a clue. I ordered an official manual from a klover will it show it in there?

they're on the video board at the top. I had a wobbly vertical once... was annoying. I don't remember if wiping it or hitting it with contact cleaner fixed it or what the deal was but it was aggravating.

I also haven't quite come up with the correct procedure for getting the board hold and the hold on the monitor to be just right.. I've been lucky up to this point I guess LOL
 
Awesome thank you guys! @thegleek please keep us posted cuz sooner or later I bet one of us will need to do something with the L1. I wonder if "theyeti" member will know? He was just working on his Sanyo this week over in the monitor section.
 
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