Nintendo Hum - SOLVED! (20EZ buzz)

I'm glad this thread happened, cause the Donkey Kong Jr. we got for the arcade last year the sound is all loud and distorted. I haven't redone a Sanyo amp board in probably 6 years, I had no recollection there was a pot on there. so I'll try dialing that pot down on DK Jr. to see if it rids it of the distortion.

the hum is tremendously bad on it too, so I'll be pulling JB as well.

thank you
 
Is this the Donkey Kong hum to which you're referring, or do I have some other animal lurking in my cabinet?


Whatcha got there is a "whir" or "siren". I believe this sound is caused by a bad transitor on the pcb. If you search the forums you'll find info on fixing your whir. The "Nintendo hum" sounds like this http://youtu.be/pC4Uzt0qm2E

-Sean
 
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I have that same siren sound on my DK. I replaced just about every transistor I could find and never eliminated that sound. I hope it works for you. Let us know your results!

I read another thread which said it was a bad cap, so who knows. I ordered a pack of 10 transistors, so I'll know in a few days. I may swap out caps if I have suitable replacements.
 
I read another thread which said it was a bad cap, so who knows. I ordered a pack of 10 transistors, so I'll know in a few days. I may swap out caps if I have suitable replacements.

I also replaced all the audio caps near the audio portion of the PCB. That didn't fix it either. The kit came from Ian Kellogg.

At this point my hum is gone with the 20k pot fix above but I've given up on the siren sound unless someone else has any ideas.
 
I just did sand1's audio mod on my Mario Bros WB last night. The hum is almost completely gone! (my MB WB used to hum extremely loud)

And maybe I'm just hearing things but the audio might even sound better? Like it's more crisp.

The new 50k (edit) pot is pretty sensitive. The smallest twist and the sound is blasting. However, once I found that sweet spot it's music to my ears. NO MORE HUMMING!

Big thanks to sand1 for sharing this fix!

20K%20pot.jpg
 
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The new 20k pot is pretty sensitive. The smallest twist and the sound is blasting. However, once I found that sweet spot it's music to my ears. NO MORE HUMMING!



Big thanks to sand1 for sharing this fix!

Use a log pot next time and it won't be as sensitive.
 
I haven't tweaked my volume pot on the PCB itself. I'll mess around there later and see if I can balance it out.

Adjusted the on board pot and still getting hum and that beeping. Could be what someone referred to as Nintendo Siren. I don't have any new 50K pots, so I can try that route yet. I relocated my original.
 
Adjusted the on board pot and still getting hum and that beeping. Could be what someone referred to as Nintendo Siren. I don't have any new 50K pots, so I can try that route yet. I relocated my original.

I was wondering about that. You moved the volume pot from the remote board to the audio amp, right?
 
I was wondering about that. You moved the volume pot from the remote board to the audio amp, right?

Yes. Didn't have any new ones and it wasn't gonna be needed any longer, so figured I'd move it. My monitor was rebuilt including the amp a couple years back, so not sure what's causing it. Or I should say, not sure why this fix isn't fixing it.
 
Yes. Didn't have any new ones and it wasn't gonna be needed any longer, so figured I'd move it. My monitor was rebuilt including the amp a couple years back, so not sure what's causing it. Or I should say, not sure why this fix isn't fixing it.

So, you moved the pot, relocated the capacitor, unplugged the connector to the remote board AND replaced the Q4 transistor, and are still getting the hum and the woowoo?
 
So, you moved the pot, relocated the capacitor, unplugged the connector to the remote board AND replaced the Q4 transistor, and are still getting the hum and the woowoo?

Didn't change any transistors on the DK pcb. I think, as a test, I'll move this amp to another of my Nintendo games and see if the hum on that game goes away. If, so the rest must be PCB related on my DK.
 
Didn't change any transistors on the DK pcb. I think, as a test, I'll move this amp to another of my Nintendo games and see if the hum on that game goes away. If, so the rest must be PCB related on my DK.

I'm only going by what I've read, but the transistor is supposed to fix the woowoo sound.
 
Fixed worked for me. Although now that the hum is pretty much gone, I can hear the warble much more now. Hopefully that will be remedied once I replace that transistor...
 
I replaced the transistor at Q4 (EDIT: I said Q5. The correct position is Q4) and the woowoo is gone! Woohoo!

I'll fix the hum at some point. To be honest, it's barely noticeable, now that the woowoo is gone.
 
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Unfortunately after this fix I still have the hum - but I do agree the audio does sound a bit more sharp (better). I wish I solved the hum, but 10/10 would mod again.

I just did sand1's audio mod on my Mario Bros WB last night. The hum is almost completely gone! (my MB WB used to hum extremely loud)

And maybe I'm just hearing things but the audio might even sound better? Like it's more crisp.

The new 50k (edit) pot is pretty sensitive. The smallest twist and the sound is blasting. However, once I found that sweet spot it's music to my ears. NO MORE HUMMING!

Big thanks to sand1 for sharing this fix!

20K%20pot.jpg
 
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