My Donkey Kong is freaking out :(

chuckfalcon

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Hi everyone, I just recently got a TKG4-UP Nintendo Donkey Kong and I love it! It played wonderfully all weekend. However, while during game play, the screen would "twitch" for a split sec on. This behavior would happen once every 3-4 minutes.

Monday I had some friends over and during game play the game just started freaking out with a bunch of garbage on the screen and it kept making "game sounds", I think it was the sound when mario dies. I turned the game off and tried starting it back up, and it still does the same "freak out stuff" and never gets back to a playable game.

So far I have reseated all of the eproms and wired connectors on the game board. I have also tested the power supply going to the game board and those voltages test good. I am also getting correct voltage to pin 11 of my Z80.

At this point I am unsure of what to do or what to check. Does anyone else have any ideas on what it could be? Any help at all and I would be most appreciative.

Thanks,
Chuck
 
rather than testing for DC across the +5 and ground wiring, you test for AC instead.

if you're seeing a lot of AC where it should be DC, then you have a problem.
 
rather than testing for DC across the +5 and ground wiring, you test for AC instead.

if you're seeing a lot of AC where it should be DC, then you have a problem.

oh, ok! That makes sense. How much AC would be too much across my +5? How much AC SHOULD I be seeing?
 
Check for ac ripple in 5v line



Andrew

I tested for AC on the board's edge connector. What I found was as soon as I touched the areas that should red 5V DC, would read, somewhere around 10V AC as soon as I touched the probe to the connection, but would quickly drop to 1V or less.

I'm not sure what this means.
 
I tested for AC on the board's edge connector. What I found was as soon as I touched the areas that should red 5V DC, would read, somewhere around 10V AC as soon as I touched the probe to the connection, but would quickly drop to 1V or less.

I'm not sure what this means.

Means it's time for a new switching power supply. Usually I don't advocate these but it'll be pretty easy to do they have ones where you don't have to kill the wiring harness just has the right plugs. If your board still has problems mikesarcade is good for repairs super cheap and the best dude.
 
Means it's time for a new switching power supply. Usually I don't advocate these but it'll be pretty easy to do they have ones where you don't have to kill the wiring harness just has the right plugs. If your board still has problems mikesarcade is good for repairs super cheap and the best dude.

ah. Well, if I was to recap my current power supply, would that fix it? I'd like to keep it as original as possible.
 
ah. Well, if I was to recap my current power supply, would that fix it? I'd like to keep it as original as possible.

It wouldn't be worth recapping you know. A power supply is a power supply. It could fry your board i wouldn't mess with it, new caps and parts will cost the same as a nice new switching ps. There are switching ps's now with the right connectors to fit in a donkey kong no hacking required. You can take the old ps and just put it in the coin box. Please don't ruin your game trust me a switching ps is the way to go with these dk's

edit here's a good one http://arcadeshop.com/nin-ps/nin-ps.htm
 
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Id also like to mention that my power supply only has "9p" and "10p" cables going to the board and tge "7p". Isnt being used

7p is for the sound Pcb on a 4 board stack. The interconnect cable does the job for 2 boards...
 
It wouldn't be worth recapping you know. A power supply is a power supply. It could fry your board i wouldn't mess with it, new caps and parts will cost the same as a nice new switching ps. There are switching ps's now with the right connectors to fit in a donkey kong no hacking required. You can take the old ps and just put it in the coin box. Please don't ruin your game trust me a switching ps is the way to go with these dk's

edit here's a good one http://arcadeshop.com/nin-ps/nin-ps.htm


I think the kit I bought to recap by DK power supply was about $12 shipped from mouser. While I 100% agree that a switcher hack is likely to be more stable since there is risk the power supply re-cap isn't done right... I personally wanted to leave the game original and so I re-capped mine and then just tested the voltages very carefully and monitored them for about a week afterword.

I respect both choices for sure - but wanted to let the OP know that the recap job is fairly easy. My capping skills are C+ to B- and I completed it without incident. If another part on the original PS went I'd probably go switcher but for now I'm happy to have the original one going.



EDIT: HERE ARE SOME HELPFUL THREADS INCLUDING A LINK TO THE MOUSER KIT
Here's the thread regarding the recap:
http://forums.arcade-museum.com/showthread.php?t=340760

Here's the mouser info from ieure:
https://www.mouser.com/ProjectManage...sID=b1cdd11ed8
 
UPDATE!!!

I took my DK board over to a friends house tonight and tested it on a KNOW WORKING cab, and it reacted the same way. SO it is for sure a board issue.

Things I have already done:
-Reseated all of the chips
-Tested all the voltages at the edge connector (all check out good)
-Swapped the out the 5A Eprom for a fresh one (still same problems)

Anyone have any other things that I should test or possible ideas of what the problem could be?
 
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