Nintendo cab speaker hum/distorted sound

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My Mario Bros.-in-Radar Scope cab gives a pretty noticeable 50 Hz hum. It also seems to sound distorted. Like a ripple over the sounds. Could replacing the caps on the sound amplifier board solve this ? Or do I need to look for anything specific ?
 
my dk jr had a bass sound pouring from it and when i replaced the caps, i thought i had the machine off. then i realized it just did wonders for the machine. it seemed that quiet =]. tho i dont know for sure if thatll fix ur prob. if youve never capped it tho, id definaly do it. you dont need to pull the monitor to do so
 
There are several electrolytic capacitors that go bad on the sound board on the Nintendo Sanyo monitor. Bob Roberts sells a seperate capkit for the sound board.
 
There are several electrolytic capacitors that go bad on the sound board on the Nintendo Sanyo monitor. Bob Roberts sells a seperate capkit for the sound board.

Unfortunately, that doesn't always correct the problem.

Darren Harris
Staten Island, New York.
 
+1

Don't get discouraged if the hum continues after you cap the sound board. It persists for many of us. I've capped both my DK and DK Jr. Sanyo's sound boards and the hum lessened a little but is still there.

There is a similar thread somewhere on Klov about this very issue. We came to the consensus that it is just something to expect from Nintendo cabs - part of the experience.

Bob Roberts said he has never worked on a Nintendo Machine that didn't have that hum.
 
There are several electrolytic capacitors that go bad on the sound board on the Nintendo Sanyo monitor. Bob Roberts sells a seperate capkit for the sound board.

OK I'll re-cap it. However, as you may remember this is not a 20EZ monitor but one with a 14" Sanyo monitor chassis (but a 19" CRT). The soundboard is different. It is combined with the controls board that regulate picture and sound volume. So Bob's cap-kit is probably not (100%) correct for this one, but there are so few caps that I will pick them up at my local electronics part shop, and let you all know if it helps. To me it sounds as though the power supply of the sound amplifier is getting fed with a rippled power supply.

I haven't cap-kitted the Nintendo Power supply so this could be also the problem. I actually tried to open the 2nd power supply I have (because it's dead) and after half an hour of hassling with it I gave up. How on earth can you open this thing up ???
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My monitor had a pretty bad hum and some weird noises even after recapping the sound board. I noticed that the board has a space for volume pot (VR371) and that C379 is mounted there (see picture), so I disconnected the cable that goes to the control pwb, moved the capacitor to the correct spot and and mounted a 50K volume pot directly on the audio board.
The hum is basically gone.
 

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My monitor had a pretty bad hum and some weird noises even after recapping the sound board. I noticed that the board has a space for volume pot (VR371) and that C379 is mounted there (see picture), so I disconnected the cable that goes to the control pwb, moved the capacitor to the correct spot and and mounted a 50K volume pot directly on the audio board.
The hum is basically gone.
I know this was forever ago, but any chance you took pics of the "after" on this mod?
I just picked up a Mario Brothers conversion with no audio, have new caps coming for monitor and audio, but want to be prepared to make this mod if its humming.

Thanks!
 
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