Donkey Kong Faint jumping sound constantly.

wadehavens

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I have a 2 board DK set that has a faint jumping sound as soon as you boot the game. I was doing some troubleshooting and I found if I rub my finger along the NE556 it would get louder. I watched a video from One Circuit on Youtube with a board that had the same thing. However, because of the other problems with the board, he never mentioned how he fixed it.

Here is the video:

https://youtu.be/k6mdj0dLjss?t=21m4s

Thanks for your help.
 
that video was awesome. I've noticed that wavy jumping sound on a few of these games. I don't know why it constantly plays, but I suspect that arrangement with the monitor sound pot that causes that obnoxious buzzing-hum-interference effect may have something to do with it.

have you seen the other thread about eliminating Nintendo hum? you basically defeat the connection to the volume pot on the monitor and install your own. I have a bag full of those at work that I could probably install later. our DK Jr. has the sound way overdriven and out of whack and I'm hoping that fixes it.
 
This thread is a bit long but might be related to the jump sound not cutting off. This was my thread and supposedly transistor Q4 or Q6 can solve this problem. For me, it didn't. https://forums.arcade-museum.com/showthread.php?t=364831

Long story short...here is the sound mine makes:

https://www.youtube.com/watch?v=gaapqFJ32Co

I have tried just about everything and still can't pin the issue down. Here is what i have done:


1. Capped the monitor
2. Replaced the audio amp with a repo from twisty wrist (now using a totally separate 3rd party amp)
3. All New audio caps on the audio portion of the CPU board
3. All new transistors on the audio portion of the CPU board (including Q4 and Q6)
4. All new capacitors on the power supply (this was a lot of work)
5. I even replaced the DAC08 chip altogether and that didn't fix it.

I about to ship my PCB off to an expert on KLOV to have it fixed because I'm about to give up.

As for the background hum sound that all Nintendo games seem to make...that is a super easy fix and you can read about it here:

https://forums.arcade-museum.com/showthread.php?t=388792
 
This thread is a bit long but might be related to the jump sound not cutting off. This was my thread and supposedly transistor Q4 or Q6 can solve this problem. For me, it didn't. https://forums.arcade-museum.com/showthread.php?t=364831

Long story short...here is the sound mine makes:

https://www.youtube.com/watch?v=gaapqFJ32Co

I have tried just about everything and still can't pin the issue down. Here is what i have done:


1. Capped the monitor
2. Replaced the audio amp with a repo from twisty wrist (now using a totally separate 3rd party amp)
3. All New audio caps on the audio portion of the CPU board
3. All new transistors on the audio portion of the CPU board (including Q4 and Q6)
4. All new capacitors on the power supply (this was a lot of work)
5. I even replaced the DAC08 chip altogether and that didn't fix it.

I about to ship my PCB off to an expert on KLOV to have it fixed because I'm about to give up.

As for the background hum sound that all Nintendo games seem to make...that is a super easy fix and you can read about it here:

https://forums.arcade-museum.com/showthread.php?t=388792

That is the exact sound mine makes. And is the exact sound that was in the video I posted. The one thing Adam from One Circuit did say was that he was going to replace the NE556. He never showed that he did, but he may have and that may be the fix. I'm gonna do that tonight. You might want to hold off on sending that board out until I'm done. I'll post the results as soon as I have some.

As far as the hum. Mine is small, but I can get a pot at the same place I'm gonna get the timer, so I'll fix that too.

Thanks!!
 
Right on! Definitely post your results, I really hope you can figure it out. I'll be watching!

I haven't been able to get to the store tonight to get the part. But i will tomorrow.

I have a question for you tho. If you put your fingers on c15 and the other caps in the row do does your chirping sound get worse? As in louder? Just wondering if that's normal. The board i have has never been worked on and i'm wondering if I should change those caps as well.

Thanks.
 
I haven't been able to get to the store tonight to get the part. But i will tomorrow.

I have a question for you tho. If you put your fingers on c15 and the other caps in the row do does your chirping sound get worse? As in louder? Just wondering if that's normal. The board i have has never been worked on and i'm wondering if I should change those caps as well.

Thanks.

I'll try puting my fingers on c15 tonight (and other caps) and report back my findings!
 
I tried putting my fingers on c15 and all the caps on my pcb and there was zero noticeable change in the background siren noise. :(
 
I tried putting my fingers on c15 and all the caps on my pcb and there was zero noticeable change in the background siren noise. :(

Bummer. And I changed out the ne556 and the only difference is now my small graphics glitch is gone. Most likely not related at all. When I put my fingers on the resistors under q6 mine gets louder. I replaced q6 with no change. I haven't replaced c22 or c25 yet. They are both in the same circuit.

Have you replaced them yet?
 
So I finally plugged my board into another amp and all the buzzing and siren sounds are coming from the board. The 20ez amp is very quiet. So I gotta have a chip or something bad for all this noise. It's more than just the siren. That may be a separate issue.

Don't know.
 
Same here....i have two dk double stacks and both have a faint 'whirring"sound...its like the very first note of the jump sound stuck on a loop....its a whirring/siren sound...i did replace q6 and it didn't fix it....and yes i did recap the sound board.

It doesnt effect any game play sounds......its just faintly in the background...ive learned to ignore it but id like to get it fixed.
 
I'm surprised that with all the boards that seem to be doing this that there isn't a concrete fix already posted somewhere. I sent a message to Adam at One Circuit in the hopes he has time to read it sometime in the future. I don't want to change parts randomly anymore.

i'll post back if I hear anything.
 
Mine has this. And I can't remember if I fixed it or just decided to live with it. You can control it though, or at least I did, by balancing out the volume pots on board, and on the monitor chassis.
 
Mine has this. And I can't remember if I fixed it or just decided to live with it. You can control it though, or at least I did, by balancing out the volume pots on board, and on the monitor chassis.

The volume of the game does overwhelm the chirping while you're playing the game. But if you have the volume about a third of the way up when you're not playing the game you can easily become annoyed by the sound. Plus mine also has some buzzing and hissing to go along with it that's NOT as a result of the 20ez audio amp. So besides the chirping sounds I need to get rid of the buzzing and hissing. It seems to be coming from the circuit around Q6. If I drag my finger around this area it gets louder.
 
It's hard to tell. The only thing close to the game board is the power supply. And I have a refrigerator about 20 feet away. Oh and the monitor of course. The monitor does have a high voltage hum, but it doesn't interfere with the audio amp. I suppose it could be coming through the video cable if there is a bad cap. I don't know. lol
 
FWIW my 2-board stack does the same thing and if I recall correctly, my 4-board stack did as well.
 
It was sheer luck that I stumbled on this thread as [email protected] goes nowhere I think. :p

Anyways if memory serves me right the problem was in this circuity right here (see attached image)

Here's my understanding on the jumping circuitry...
The oscillator that generates the jumping sound is always running and feeds into D7. But when the game doesn't want to hear it, it turns Q5 off. This means current flows from 5V across R30 and R29 until the capacitor C17 is charged. Once that happens the voltage on C17 is high enough to turn on D6. Once D6 is on, the voltage on the other side of D6 is so high that D7 never turns on (which is what you want) and the sound never makes it to the amp.

When you want to hear the sound, Q5 turns on, discharges the cap and this causes D6 to turn off completely. This means current (and this the sound) from D7 flows freely to the amp.

The problem in my case was that the voltage across D6 wasn't high enough to keep D7 from opening up. If it's not, D7 opens and closes juuuust slightly and that's why you hear the faint sound. If memory serves, I tried replacing D6 but no difference so I then replaced R29 with something a bit smaller. 2k or even 1k perhaps... I honestly can't remember but it was lower than 10k and that ensured we had a voltage high enough to keep D6 fully on and thus D7 off.

So I would say try replacing R29 with say a 5k and see how that affects the sound. If it's lower but still present then maybe go lower.
 

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