Donkey Kong Switching Power Supply Question

fmetz374

Member
Joined
Sep 10, 2011
Messages
43
Reaction score
9
Location
New Baltimore, Michigan
I've been searching through the forums for an answer to getting a switching power supply to work in a 2-board Donkey Kong but it appears most posts are quite old going back to 2010/2011. I apologize in advance if I am asking a duplicate question that has already been answered.

I purchased a switching power supply conversion kit from Arcade Shop found here:

http://www.arcadeshop.com/i/545/nintendo-power-supply-conversion-kit.htm

After installing, I am now getting vertical graphics corruption that I've seen other people with this issue refer to as "sprites". In any case it appears this is due to the -5V power rail not delivering either the correct voltage or amperage to the DK 2-board set, thus causing graphics corruption.

I can switch back to the 37 year old Nintendo power supply and the game goes back to working flawlessly. For those that are asking why I'm attempting to swap out a working power supply, my reason is that after 37 years it is likely time to replace or it soon will be time to replace. :)

The power supply that came with the kit was a Suzo Happ Power Pro. I did a meter reading on the power supply with no load and only AC connected to it. While the +5V terminal reads +5V, the -5V terminal only reads -4.2V. I suspect this is why I am getting the graphics corruption on my board. I can adjust the 5V potentiometer on the power supply to get the -5V terminal to read -5V, but then the +5V terminal reads 6V's which is much too high for the DK PCB.

Just curious if there is a different power supply I can use? I've attempted to go as high as 5.2V on the PCB and this reduces the graphics corruption but does not eliminate it.
 
i am confused if the old power supply works why are you trying to replace it?? the original power supplies short of needing a cap kit will generally last another 30 years and no switchers can say that. plus part are easily and readily available for the original PS at many places including our site.
 
Thanks for the suggestion of recapping the Nintendo Power Supply. I've purchased a number of cap kits from your site for my Atari AR boards and have had great success. I neglected to mention that the original owner of my Donkey Kong machine has spliced into the two 9P and 10P harnesses and tied the +5V to a separate 5V switching power supply. This leaves the original Nintendo Power Supply providing only +12 and -5V. This leads me to believe there's already an issue with the +5V on the Original power supply. I was hoping to just put in a modern switching power supply that is readily available and relatively easy and inexpensive to swap out. I have experience rebuilding the Atari AR boards so maybe rebuilding a Nintendo Power Supply is the way to go too. Appreciate the help.
 
Thanks for the suggestion of recapping the Nintendo Power Supply. I've purchased a number of cap kits from your site for my Atari AR boards and have had great success. I neglected to mention that the original owner of my Donkey Kong machine has spliced into the two 9P and 10P harnesses and tied the +5V to a separate 5V switching power supply. This leaves the original Nintendo Power Supply providing only +12 and -5V. This leads me to believe there's already an issue with the +5V on the Original power supply. I was hoping to just put in a modern switching power supply that is readily available and relatively easy and inexpensive to swap out. I have experience rebuilding the Atari AR boards so maybe rebuilding a Nintendo Power Supply is the way to go too. Appreciate the help.

those nintendo power supplies are very easy to fix and super reliable when done and i have special sized caps for them in our kits so they fit perfectly and they are the best quality caps and you won't find any vendor kits with even close to as good of caps used as in our kits.
 
The tricky part is to get it open without having to use an angle grinder I think.
Nintendo used the softest screws they could find I suppose.

Maybe something is wrong with +5V in your PSU but it could also be that the former owner did not know that you can adjust it inside the PSU and took the "easy" way out throwing in a switcher.

Atleast one of my DK boards is very sensitive to low +5.. Get glitchy sprites at 4,95 and works perfect at 5,1.
I dont think your low -5V is causing your issues.
 
I've been searching through the forums for an answer to getting a switching power supply to work in a 2-board Donkey Kong but it appears most posts are quite old going back to 2010/2011. I apologize in advance if I am asking a duplicate question that has already been answered.

I purchased a switching power supply conversion kit from Arcade Shop found here:

http://www.arcadeshop.com/i/545/nintendo-power-supply-conversion-kit.htm

After installing, I am now getting vertical graphics corruption that I've seen other people with this issue refer to as "sprites". In any case it appears this is due to the -5V power rail not delivering either the correct voltage or amperage to the DK 2-board set, thus causing graphics corruption.

I can switch back to the 37 year old Nintendo power supply and the game goes back to working flawlessly. For those that are asking why I'm attempting to swap out a working power supply, my reason is that after 37 years it is likely time to replace or it soon will be time to replace. :)

The power supply that came with the kit was a Suzo Happ Power Pro. I did a meter reading on the power supply with no load and only AC connected to it. While the +5V terminal reads +5V, the -5V terminal only reads -4.2V. I suspect this is why I am getting the graphics corruption on my board. I can adjust the 5V potentiometer on the power supply to get the -5V terminal to read -5V, but then the +5V terminal reads 6V's which is much too high for the DK PCB.

Just curious if there is a different power supply I can use? I've attempted to go as high as 5.2V on the PCB and this reduces the graphics corruption but does not eliminate it.

dumb question maybe but you're using a ribbon cable on the 2 board stack correct? And measure the 5V at one of the TTL chips/EPROMS on the board. That adapter can cause a voltage drop so you may not be getting the same voltage at the PCB that you are at the PS.
 
A couple of random points in reply to your posts:

The -5v being low when the board isn't connected — that is probably due to this voltage being unregulated and no load being on the board. I don't think that's your problem.

I also echo repairing your harness and rebuilding the original. Very easy project once you get it open.

That being said - if you want to push through getting the switcher to work I am confused by one thing in your posts. Does the game work perfectly with the old setup? You mentioned the 5v being hacked.
 
Hello and thanks for your post. The 5V is hacked. The original owner put in a 5V switching power supply and cut the 5V wires on the original harness and tied them into this 5V switching power supply. I did order the 9P and 10P replacement harnesses from Mikes Arcade. Using the new replacement harnesses I seem to have issues with the switching power supply and graphics corruption. When I go back to the spliced harnesses and 5V switching supply all seems to work fine. Again the +12V and -5V are coming from the Donkey Kong power supply in this configuration. I'm leaning towards rebuiilding the Nintendo power supply at this point. I've watched a video of this on YouTube and it looks very easy. I was hoping for a quick fix and failed. :)
 
Thanks for your post and this is not a dumb question at all. I appreciate all input. I have measured the voltages at the TTL chips/EPROMS on the board and I've gone as high as +5.2V to see if I can get the graphics corruption to go away. At +5.2V it is lessened but does not completely go away. I'm not comfortable going any higher as I'm sure this would shorten the life of my PCB.
 
In response to behrmr's post, I am familiar with the ribbon cable, but for this 2-board set I have two separate 9-pin and 10-pin harnesses that go to each board.
 
In response to brainmegaphone's suggestion that the -5V reading low due to it being unregulated and without load, I went back and measured it with load. I actually bumped the +5V to 5.37V under load. This results in 5.25v at the chip/eeprom level. (I really don't want to test any higher than 5.25v at the chip level). When I measure the-5V terminals under load it only shows -4.82V. This seems to indicate to me that if it's only -4.82V at the power supply it would be even less at the chip/eeprom level. This is why I'm questioning the -5V coming from the power supply.

Does anyone have a method for measuring -5V at the chip/eeprom level on donkey kong?

Again, really appreciate all the responses from everyone! This community is awesome!
 
Have you tried calling or emailing Steven Gregory @ Arcadeshop? He's pretty helpful with installing his stuff. You may just need a different PS.
 
I did email Steven Gregory. He asked me to try a different power supply. I actually purchased a total of 5 kits from him. I installed switching power supplies in Donkey Kong Jr, Mario Bros, Popeye, and Pac Man. All of them installed without issue. I tried another power supply since I had a total of 5 that I purchased from arcade shop. I had the same results. They are Happ Power Pro switching powers supplies. Coincidentally the other power supplies also measure a lower -5v while the +5 terminal actually reads 5V.
 
Hello and thanks for your post. The 5V is hacked. The original owner put in a 5V switching power supply and cut the 5V wires on the original harness and tied them into this 5V switching power supply. I did order the 9P and 10P replacement harnesses from Mikes Arcade. Using the new replacement harnesses I seem to have issues with the switching power supply and graphics corruption. When I go back to the spliced harnesses and 5V switching supply all seems to work fine. Again the +12V and -5V are coming from the Donkey Kong power supply in this configuration. I'm leaning towards rebuiilding the Nintendo power supply at this point. I've watched a video of this on YouTube and it looks very easy. I was hoping for a quick fix and failed. :)

You have a weird issue for sure and it seems the person hacked the supply because they likely had the issue you have now originally.

I guess my best suggestion for what it is worth is to pick a path and focus on that. I'd rebuild the original... but either path is fine I'd just focus on one.

One other thing - while I doubt it is your PCB it might be worth testing another PCB or testing your PCB in another persons cab. Just to rule stuff out. I don't suppose you have another Nintendo cab around...?
 
Correct me if Im wrong but
I dont think the low -5V is an issue? On all switchers I ever measured -5 is always lower than +5

Had to check on my bench, took Mikes Nintendo To Jamma and without load it measured +5.1 -4.5 & +11.5.
With a DK board hooked up I get +5.0 -4.5 +11.5
Working great
 
Good to know. Thanks for confirming the voltages. I'm by no means an expert on arcade repairs. I only know the same power supplies work fine on Donkey Kong Jr, Mario Bros., and Popeye. I only know that Donkey Kong is more reliant on -5V based on what I've read from other people. I'm just a novice. I may try another brand of switching power supply or just rebuild the original now that I know how easy it is.

Appreciate the follow-up!
 
So I thought I'd wrap up this thread with my final results. Steven at Arcade Shop confirmed for me that the graphics corruption I was experiencing was likely due to an issue with the -5 voltage on the video pcb. In measuring the output from the Nintendo power supply it is a solid -5.2V. The switching power supply only put out -4.3v. With the new switching power supply I had graphics corruption and with the Nintendo Power Supply the graphics were absolutely perfect.

I also purchased a Nintendo PP-7B cap kit from https://www.arcadepartsandrepair.com/. I rebuilt my Nintendo Power supply and even with the new cap kit it will not provide +5 volts so now I understand why the original owner put in a separate switching power supply for the +5V.

So now I'm going with a compromise. I'm going to use the ArcadeShop switching power supply for the +5V and I'm going to use the freshly recapped Nintendo Power Supply for the +12 and -5V's.

I am curious if there are switching power supplies that will actually put out -5v. It appears my DK board set is very sensitive to having an actual -5V. I can't explain it.

Thanks again for everyone's input. This community is great and I hope my experience helps someone else out in the future. :)
 
if your only missing the +5 and all the caps are replaced then there is not much else in that circuit. there is only an ic and a small amount of resistors and diodes which its one of the easiest circuits to fix and then all your voltages can come out of that one power supply.
 
Back
Top Bottom