Donkey Kong recapped monitor has background hum and alarm sound

[vwalbridge]

I just recapped the Sanyo 20EZ on my Donkey Kong. I also recapped the sound board as well. Before I recapped it, the picture was like a wavy flag and it didn't have any sound.

Now that the recap is done, there is no more wavy flag but I do have redish/purpleish vertical lines about every inch going vertical. See picture below. (I have not fooled around with the pots near the neck board or flyback yet. I have only adjusted the standard pots near the sound board. ) I'm hoping this is just a pot adjustment.



However, the bigger problem right now is the sound. The second I turn the machine on, I can briefly hear the "spring" sound that DK makes when it boots up. But then I just hear it humming. If I listen closley, its like its playing the first note rapidly like a broken record. What's even more strange is that when I coin up and start a game, I can't hear music, but I can hear DK stomping. That's it. See video below:

I've never capped a monitor before so I could have easily messed it up. Did I crowbar something? HELP!

http://www.youtube.com/watch?v=vl1bEBO3RjM&feature=youtu.be

[vwalbridge]

Ok, I figured out my "lack of sound" issue. I had to turn up the pot on the DK PCB itself. However, the sound effects seem "off" to me. For example, the jump sound is twang-ie in nature. I'll have to upload a video of that. And I also still have those vertical lines. Google-ing it sounds like jailbars? The image also appears to be shifted to the right too much.

Please tell me I don't have to cap this thing again.

So here are my current issues:

1. Vertical lines (jail bars?)
2. Twangy sound when mario jumps
3. Constant background humming

Yay...

[vwalbridge]

Ok...well, things are getting better.

1. Vertical lines (jail bars?) FIXED -  Just needed to fine tune the brightness pot on the flyback and the main brightness pot. It's a fine balance between the two


2. Twangy sound when mario jumps (maybe I'm just hearing things on this)
3. Constant background humming
3. B+ is at 110. I need to adjust it down to 108. It's been 110 from the factory because I can still see the security paint on it

[harveybirdman]

I have no idea on your questions but congrats on the capping!

[grantspain]

don't worry about your b+,it is well within range

[CraftyMech]

Turn down the screen pot on the flyback and see if the vertical lines go away. They look like retrace lines from the photo you provided, but hard to tell.

There are horizontal/vertical position pots on the DK pcb for adjusting the centering of the picture.

[vwalbridge]

Turn down the screen pot on the flyback and see if the vertical lines go away. They look like retrace lines from the photo you provided, but hard to tell.

There are horizontal/vertical position pots on the DK pcb for adjusting the centering of the picture.

Thanks! You were right. It was the pot on the flyback. Picture looks awesome now. Also, I found the pots on the the PCB itself and centered the image. It really looks fantastic now.

However, the plot thickens...the sound was messed up. The music worked and the sound effects worked but there was this constant buzzing/siren sound coming from the speaker.

In my attempt to isolate the culprit, I unplugged the P9 able from the power supply....then the sound stopped. Ok, pluged that cable back in and now I have NO sounds whatsoever.

I started another thread over at KLOV and they suggested I get a logic probe and start checking some chips on the PCB. 

My logic probe arrives on Wednesday.

[yotsuya]

However, the plot thickens...the sound was messed up. The music worked and the sound effects worked but there was this constant buzzing/siren sound coming from the speaker.

In my attempt to isolate the culprit, I unplugged the P9 able from the power supply....then the sound stopped. Ok, pluged that cable back in and now I have NO sounds whatsoever.

I started another thread over at KLOV and they suggested I get a logic probe and start checking some chips on the PCB. 

My logic probe arrives on Wednesday.

You didn't unplug and plug those cables while the game was ON, did you? A lot of those boards aren't plug and play with power.

[vwalbridge]

Ugh...yea I did.  I wasn't paying any attention and did it while the game was on. I did it twice. The first time it didn't care, the 2nd time the sound never came back on.

The good news is that it still comes back on and the game plays fine. Just no sound at all.

[yotsuya]

Ugh...yea I did.  I wasn't paying any attention and did it while the game was on. I did it twice. The first time it didn't care, the 2nd time the sound never came back on.

The good news is that it still comes back on and the game plays fine. Just no sound at all.

Yeah, I learned that the hard way myself.

[vwalbridge]

Ugh...yea I did.  I wasn't paying any attention and did it while the game was on. I did it twice. The first time it didn't care, the 2nd time the sound never came back on.

The good news is that it still comes back on and the game plays fine. Just no sound at all.

Yeah, I learned that the hard way myself.

Was it a DK you learned on by chance? Cuz that would be swell if you knew the fix.

[yotsuya]

Ugh...yea I did.  I wasn't paying any attention and did it while the game was on. I did it twice. The first time it didn't care, the 2nd time the sound never came back on.

The good news is that it still comes back on and the game plays fine. Just no sound at all.

Yeah, I learned that the hard way myself.

Was it a DK you learned on by chance? Cuz that would be swell if you knew the fix.

Mine was a force feedback board on my racer. I blew a transistor.

[DeLuSioNal29]

That sounds like a board issue to me.  Did you double check that all the chips are seated correctly and no pins are missing.  Also, check the edge connectors to make sure they are not dirty.

D

[vwalbridge]

That sounds like a board issue to me.  Did you double check that all the chips are seated correctly and no pins are missing.  Also, check the edge connectors to make sure they are not dirty.

D

Thanks DeL. However, some things have changed since then. Let me get this situation more up to date:

I had some bread board wires lying around so I sodered them to the end of a headphone jack. (See below)



Then I plugged the breadboard wires into the DK PCB audio port. And the other end into the "audio input" jack on a set of desktop speakers. Fired up the machine and BOOM! I have audio. See video below:



I also ohm'ed out the DK speaker itself and also did the 9v battery trick and the current speaker definitely works. I also checked the continuity on the wires going from the amp to the speakers and that checked out.

So that pretty much only leaves 3 things it could be:

1. The audio amp

2. The Volume pot board

3. The transformer between the audio amp and the speaker

I took the audio amp back out again and looked it over. I triple-checked all the new capacitors I installed and even re-flowed all the solder points...new and old. Put it back in the cab and...still no audio.

So I guess there is probably something else wrong or that amp is just shot. I'm really surprised because I'm pretty sure I nailed the re-cap on it. Oh well, getting closer!

NEW UPDATE:

I've been really digging around and I've got a really strong theory that I blew the R383 Fusible Resistor on my audio amp.


I've been warned to check this 65 cent part when you don't have audio but are sure that everything else checks out. I purchased a new one from Twisty Wrist Arcade

Some audio cap kits come with this part, some don't. The kit I ordered from Ian Kellogg does not include this part. Crossing my fingers this fixes my problem because I'm fresh out of ideas after this.

[yotsuya]

Hopefully you just popped that when you tried a hot swap.

[harveybirdman]

Fingers crossed dude, these kinds of things can be a ---smurfette--- when your "last" idea that your waiting on doesn't work out.  Don't get discouraged, it's going to be super awesome when you finally here that sunnabitch fire up.

[vwalbridge]

Thanks yotsuya and harverybirdman. I need as much moral support that I can get.

UPDATE from last night:

Got my new audio cap kit from twisty wrist that includes that special R383 fusible resistor. I de-soldered the old one and soldered on the new:





and...BOOM!

...still NO sound. 

But, I'm still totally convinced the problem is somewhere on the audio board. How do I know that? Well, I took some alligator clips and hooked them directly to the DK's audio headers and then straight to the speaker. (Thus bypassing the amp completely) And this gives me sound. Very quite sound, but I hear the game nonetheless.

So...actually have 2 more things to try:

1. The rest of the fresh cap kit from twisty wrist. Essentially re-capping the entire audio board for the 2nd time.

2. Buying an entirely new repro audio board from twisty wrist.

The current score between me and fugly DK:

fugly DK: 1
vwalbridge: 0

[yotsuya]

Just buy the new board. Cut your losses and play some DK.

[vwalbridge]

Just buy the new board. Cut your losses and play some DK.

If the audio board re-cap doesn't work tonight then I will be getting the reproduction board. I've had a mouthful of work on the DK cab so far and haven't even tackled anything major yet.

If I ever own a 2nd arcade machine, I sure as hell ain't gonna pick one up as bad as this one. 

[harveybirdman]

If it were me, I'd be pissed enough to order the new board but then go down to my local electronics shop and by replacements for every other resistor on that damn thing and swap them all just because the damn thing made me mad.

[vwalbridge]

If it were me, I'd be pissed enough to order the new board but then go down to my local electronics shop and by replacements for every other resistor on that damn thing and swap them all just because the damn thing made me mad.

LOL +1...at this point, I almost have to make the original board work. It's become personal and I really want to beat this issue.

[obcd]

You got a strong theory that you blew a resistor....
Did you measure that resistor?
Did you check the transformer between the audio board and the speaker?
You could use an mp3 player or even a simple smartphone as audio source to check the audio amp and transformer after it.
You already have the cable with a 3.5mm jack that might fit the headphone socket.
Just place a 15 - 33 ohm resistor in serie with it to ensure you don't short that system it's audio amp.

[baritonomarchetto]

Just place a 15 - 33 ohm resistor in serie with it to ensure you don't short that system it's audio amp.

Interesting: do you mean between the headphone jack and the amp?

[obcd]

Yes, in serie with the cable. A headphone normally has an impedance of 30 ohms. Most speakers are 4 ohms or 8 ohms. That impedance is 2 low and might overload the amplifier chip in your mp3 or smartphone. Normally, those are protected against such misbehavour, but I prefer to play safe. If there is a resistor in serie, the impedance can never become lower than the value of that resistor. It will decrease the volume of the sound, but you should hear something silently. Only use one channel of the mp3 / smartphone and leave the other disconnected.

[vwalbridge]

LATEST UPDATE:

With fugly kong it seems to be 2 steps forward and 1 step backwards.

After completely re-capping the audio board will all new caps and transistors. I now have sound again!

However...

The game sounds are "skewed" in a way. Almost like they are being played by an instrument that is badly out of tune. And DK's stomping is a little "crackling"

Here is a video of how it sounds now:  (Listen closely...especially the last 4 notes that play after Jumpman dies. Really wonky sound)



I have no idea why replacing the new caps and transistors with new caps and transistors got my sound back. But...got back bazaaro sound. 

There must be something fundamentally bad with this sound board but I have ran out of parts to swap. (I do have a brand new speaker from Mike's arcade that I will swap tonight but I seriously doubt that will help)

So a reproduction audio board is now in order.

Stay tuned....I vow to close this thread with a DK that doesn't sound drunk.

[vwalbridge]

2 steps forward...one step back. THIS is the theme for me and my DK problem right now.

Latest update:

I received my NEW audio amp from Twisty Wrist.


...and installed in the monitor frame. It's a 1:1 fit.


Then powered on my DK and BOOM! I HAVE SOUND AGAIN! WOOT!



BUT...this evil DK still has some fight left in her...

I still have that background "siren" sound present. I'm practically back where I freakin' started. Here is a quick clip of that horrendously annoying sound.



But like I said, I'm NOT closing this thread out until I fix this audio issue 100%. So sometimes when a door closes, another one opens. Just when you think you have tried everything, something else pops up you can try.

Therefor at this point, the "siren" sound is definitly coming from the PCB itself. In fact, anyone that owns a DK cab knows that when you first power it on. There is a "spring" sound effect. That's actually the jump sound from Jumpman. Well....if you have a particular Transistor bad on the PCB, that sound never fully shuts off and just keeps repeating in the background and sounds like a "siren" going off.

So here is what Mike's Arcade repair log states on his website:

Problem: Background tone always present, walk sound off.

Sounds like the walk sound never completely cuts off.

Solution: replace transistor Q6 on the CPU board, a 2SC 1815

I've ordered 2 of these 8 cent transistors. I'm hoping this is what finally puts this issue to bed.

Current Score:

Fugly DK: 2
vwalbridge: 0

I currently feel like this right now trying to track down this issue:

[harveybirdman]

Get that sunnabitch.

Nice graphical representations.

[vwalbridge]

Get that sunnabitch.

Nice graphical representations.

Thanks harveybirdman! I have to keep it funny or I might lose my mind. 

[DeLuSioNal29]

Keep us posted!

[vwalbridge]

Welp, I'm running in place right now with this audio issue. 


I received a 100-pack of new 2SC 1815 transistors. Cost a whopping $4.


I then replaced the Q6 transistor on the PCB. I also went ahead and replaced transistor Q4 as well since I was in there. Q4 can sometime relate to audio issues.


However, I STILL have that annoying buzz sound combined with that background "siren" noise. Literally nothing has changed. I still have yet to replace transistor Q5. I guess that I might as well try that one too. I'm now starting to wonder if one of the blue caps near the audio portion of the board is bad. There are about a dozen of them around there so it could take a while to narrow that down.



Man, I'm getting really exhausted with this issue. I'm starting to wonder if I'm even going down the right path anymore. Allegedly, that buzzing sound is normal on DKs but I don't remember it being that loud.

[DeLuSioNal29]

Ask Ian to help you out. I talk to him daily on the John's Arcade chat. He can make a custom kit for you to get the rest.

[vwalbridge]

Ask Ian to help you out. I talk to him daily on the John's Arcade chat. He can make a custom kit for you to get the rest.

Thanks DeL. I just started a thread over at Johnsarcade yesterday. He is already helping me. Ian is a Rockstar!

http://www.johnsarcade.com/forum/index.php?topic=2960.msg16078#msg16078

[jennifer]

   I feel for you friend, Really, I do, But that's how it gets gone... A scope, and a good cap tester would be a invaluable with this ,But Jennifer think perhaps I would be checking the filter on the P/s at this point.

[vwalbridge]

   I feel for you friend, Really, I do, But that's how it gets gone... A scope, and a good cap tester would be a invaluable with this ,But Jennifer think perhaps I would be checking the filter on the P/s at this point.

Thanks Jenn! I could use all the sympathy I can get. 

I really bit off a huge bag of hurt with my first arcade machine and restore in one. I'm quickly realizing how valuable the "right tool" is.

I've got one more thing to test tonight and then it's new audio PCB caps and power supply caps.

[jennifer]

   I cant imagine trying to do that without the right tools, At best it becomes a guessing game, Caps (even new ones) have some curious properties, a scope on the flea pay can be had very reasonably, I paid like 50.00us for my first little Phillips (awesome machine, I still use it)... A bad ground can cause your issues too, especially at a connector, or pin, Gently moving it (don't unplug under power just gently wiggle)and tapping on them with the game on might just be the answer your searching for.

[vwalbridge]

At best it becomes a guessing game

You got me pegged for sure.  I started off guessing...then thought I had it...now I'm right back to guessing again. By the time I'm done, I'll have everything (within reason) replaced!

I'm definitely using the "brute force" method. At some point I'm going to pull out the bad part. But not because I knew it was bad...there would just be nothing left to pull! 

I'm going to test your "bad ground" theory tonight. That sounds good... thanks for the tip. 

[vwalbridge]

Capacitor Carnage...

This is what my life feels like. Also sounds like a cool name for an arcade machine: "Capacitor Carnage"  Somebody get on that.

Anyway...

My shenanigans of chasing down this audio issue continue. So my very cool cap kits arrived from Ian Kellogg. One kit is for the audio capacitors on the DK PCB and the other kit is the capacitors for a DK power supply. I just really love how organized his kits are. He actually made the PCB kit special for me and then just decided to stock it as a regular kit.





I decided to do the audio PCB capacitors first. In the image below, I have now replaced every single audio capacitor and transistor inside the red line. 16 caps and 7 transistors to be exact.



I then hooked the board back up into my DK, turned it on and....I STILL have that annoying hum mixed with the alarm sound in the background. Sigh. The overall sound of the game might be sliiiighly better. But maybe my ears are just playing tricks on me now. Good news is that I didn't make it worse...but I certainly didn't outright fix it.

So....I think Jenn might be correct. The last place I have not really poked around is the power supply. So, I'll be putting a new cap kit in the power supply next. Might as well, its 35 years old and has never been capped.

For those of us keeping score:

Fugly DK: 4
vwalbridge: 0

[harveybirdman]

Never give up! Never surrender! Churchill that mother ---smurf---!

[DeLuSioNal29]

Keep up the fight!  Hope that you get it resolved!

D

[vwalbridge]

Never give up! Never surrender! Churchill that mother ---smurf---!

Keep up the fight!  Hope that you get it resolved!

D

  You guys are awesome. Can't wait to hang out at ZapCon.