DK Audio Board keeps frying

lifereboot

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Hey all,

I used my new DK upright daily for nearly 5 months with no audio problems. Recently, I was 30 minutes into a game when the audio started screeching popping and cracking. To correct the broken audio I ordered a Nintendo audio board cap kit but I botched the soldering job (stupid), so I bought another Nintendo audio board from a KLOV member to replace my broken one. When I swapped in the replacement audio board my DK worked 100% again...

...for only one week. The same thing with the screeching popping and cracking happened again yesterday, after about 20 minutes of gameplay.

This time, I was making a gameplay recording, so I actually got footage of the audio board as it failed. Here is the youtube link. You can watch the whole thing if you want to see my machine and stuff, but the link will take you to the stage where the audio fails: http://www.youtube.com/watch?v=Hms4mFKIVLY&t=18m

I have a THIRD audio board in the mail coming to me, since replacing the audio board fixed the problem last time. What I'm concerned about is that something is causing these boards to fail and I'm not sure what.

Could it be just bad luck? The capacitors went in both boards, and there's nothing really wrong with my machine that's causing these boards to fail? Or is there something wrong in my cabinet that I should adjust before installing my third audio board once it arrives?

If you watch the video from the 18min mark, you'll see that towards the top of the level it screeches, and then the sounds that were previously working are missing. The "collecting points" noise that you get when jumping over a barrel or collecting a prize is gone. The noises for the story animations are gone. The only sounds that seem to remain are the DK "pounding" noise and the Jumpman walking noise.

Would appreciate your input. Thanks!
 
Here's the audio board I'm talking about that I keep replacing:
na1.jpg
 
With that symptoms I usually look for ac.

After watching video;there are several sounds paying for some time, maybe add a fan for audio amp and heat.

post a pic of your board in its home location.

I am trying to see what is physically near it and condition

hell; post a pic of all of them boards
 
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If you want to see the inside of the cab where the game PCBs are mounted you can refer to much earlier in the video: http://www.youtube.com/watch?v=Hms4mFKIVLY&t=1m

Those boards are awfully close to ac (transformer) wires too. That transformer has a magnetic field that can really mess with audio! My C.B. friend found this out. His new Uniden HR2510 was not working right, when I got there he had it sitting on his 50A supply.
 
If it is like mine the fuseable resistor blew. That isn't included in bob's deluxe kit.

I am not at my computer but look for my thread, I replaced it with a resistor and fuse in series.
 
If it is like mine the fuseable resistor blew. That isn't included in bob's deluxe kit.

I am not at my computer but look for my thread, I replaced it with a resistor and fuse in series.

The fuseable resistor is grey and right near jc connector. I don't remember the #
 
Here's the audio board I'm talking about that I keep replacing:
That's just an audio amplifier. I don't hear screeching, popping, or cracking in your video. However what you said:

then the sounds that were previously working are missing. The "collecting points" noise that you get when jumping over a barrel or collecting a prize is gone. The noises for the story animations are gone. The only sounds that seem to remain are the DK "pounding" noise and the Jumpman walking noise.

Cannot possibly be a broken audio amplifier. You don't get "some but not all" sounds with a broken audio amplifier. Something else, possibly your gameboard, is messed up. You are spinning your wheels replacing capacitors or replacing that board regarding that description.
 
I don't hear screeching, popping, or cracking in your video

The audio problems start at 18:45 in the video. After it happens, the "points obtained" noise like jumping over a barrel or collecting a prize is gone (the sound kind of sounds like "puerto RICO" to me, you can hear it earlier in the stage as I jump barrels before the scratching sounds when I grab the top hammer)

Then you hear me SIGH very audibly before the next stage begins, because I know the audio amp has been killed again. There is no intro music before the next stage begins, the background music is gone, the music when you're wielding the hammer is gone, the dropping noise from Kong falling when the stage ends is gone, and the victory theme when you save the lady is gone.

For clarity, once the amp fries like at 18:45, the sounds are gone for good. I can reboot the machine or play after the cab has been sitting off overnight, but the sounds never return. I basically play the game with half the sounds until I replace the amp.

When this first happened with my original amp, I tried an audio board cap kit per this thread but like I said I botched the soldering job like an idiot. I sought out a working replacement amp, bought one from KLOV member dj dns, and once I received it, I installed it and the sound was back to normal for a whole week. It was the only thing I changed and it fixed it, for a while at least.

Then on Monday, like you can hear in the video, the screeching happens again, ruining my new amp...
 
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I can't think of anything which would cause the caps to fail so prematurely other than excessive voltage. For some reason you haven't mentioned what voltages are present on the power input to the board.
 
I basically play the game with half the sounds until I replace the amp.

I'm basically going to repeat what Joey already stated......It's not your audio amp!

The audio amp can not select certain sounds to amplify, while others are silent. The audio amp amplifies ALL AUDIO. You have something going on with the motherboard. More than likely......a crappy IC socket. Sometimes it's "biting" the chip good enough, other times...it's not.

Edward
 
The audio amp can not select certain sounds to amplify, while others are silent. The audio amp amplifies ALL AUDIO. You have something going on with the motherboard. More than likely......a crappy IC socket. Sometimes it's "biting" the chip good enough, other times...it's not.

Edward

I am going to disagree with you on that point, as you can see in this video, some sounds are not amplified, others sound weird. No jump sound:



After I rebuilt the amp and replaced the fuseable resistor at R383 with a resistor and fuse it works fine.

Here is the resistor in question:
IMG_20110929_213351.jpg



The board on my DK was fine. Here I connected the audio out from the board to amplified PC speakers and it sounded right:




Then when after I capped and replaced fuseable resistor at R383:



Here is the whole thread where I fixed it:
http://forums.arcade-museum.com/showthread.php?t=203646
 
Thanks for everyone's input.

It's hard to admit but I was wrong about the amp. It's really surprising since from my perspective, replacing the amp seemed to fix the same problem last time.

I took Joey and Edward's advice and looked to my boards for a problem. Some of the socketed chips looked a little gummy so I removed them and cleaned the legs and replaced them. Now the sound works fine. Thanks guys.

Thanks for your support Tighe with your vids and amp experience. Like you, the fact that the digital/analog sounds were behaving differently made me wonder.

I suppose that the first time this was "fixed" when I replaced the amp, the true culprit was that I was moving my cabinet back and forth from against the wall to the center of the room. Maybe wrestling the cabinet around back and forth affected the "bite" on the socketed chips.

I'm back in business now. Thanks again!
 
Nothing really fantastic to add to this thread from me, other than to note that this further reinforces the steps that must be taken when troubleshooting arcade equipment: power, socketed chips, connectors, etc. The basic stuff.

Glad you got it fixed, and glad it was simple!
 
I am going to disagree with you on that point, as you can see in this video, some sounds are not amplified, others sound weird. No jump sound:

The thing is......approximately half of lifreboot's sounds were fine. This eliminates the audio amp from the equation. All sounds go through the audio amp. It's impossible for it to pick-and-choose what it amplifies. Now, the sounds being fed to the amp are varying in frequencies....and some are digital signals while others are analog signals. How it "interperts" these can be very different (as in your case....some sounds missing, some in odd tones, some scratchy, etc.).

If all sounds are being affected in some way or form.....it could be the audio amp board (it could still be the motherboard, too). If some sounds are affected, while others are perfectly normal......it will never be the audio amp.

One side note.....these Sanyo/Nintendo audio amps take a pounding. If your amp still has the original factory Sanyo (the Sanyo name is printed on the caps) capacitors installed......it needs to be re-capped!

Edward
 
The thing is......approximately half of lifreboot's sounds were fine. This eliminates the audio amp from the equation. All sounds go through the audio amp. It's impossible for it to pick-and-choose what it amplifies. Now, the sounds being fed to the amp are varying in frequencies....and some are digital signals while others are analog signals. How it "interperts" these can be very different (as in your case....some sounds missing, some in odd tones, some scratchy, etc.).

If all sounds are being affected in some way or form.....it could be the audio amp board (it could still be the motherboard, too). If some sounds are affected, while others are perfectly normal......it will never be the audio amp.

One side note.....these Sanyo/Nintendo audio amps take a pounding. If your amp still has the original factory Sanyo (the Sanyo name is printed on the caps) capacitors installed......it needs to be re-capped!

Edward

Did you hear my video? It was missing sounds until after I replaced that one fuseable capacitor. Even after I capped and replaced the transistors the jump sound was missing. :D
 
Those amps run from some nasty high voltage supply off the monitor. Be careful when working on them.
 
Did you hear my video? It was missing sounds until after I replaced that one fuseable capacitor. Even after I capped and replaced the transistors the jump sound was missing. :D

It could be the tiny speakers in my laptop, but yeah I listened to the video.....all of your sounds seemed affected.

That fuseable resistor goes bad....a lot. When capacitor C378 degrades to a certain point.....it'll kill that resistor. The cap kit guys really should include that resistor in their kits.

Edward
 
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