Zaxxon Cap kit on PCB sound section... HOLY MOLY!!

CyberDude

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Im going to be doing the cap kit for my ZAXXON PCB as soon as my caps show up in the mail. There are thirteen 2.2uF 50v capacitors on the sound portion of the board that need replacing. Yes they are labeled on the front of the PCB and I am able to track them down fairly easy but when I flip the board over to identify where to desolder them HOLY MOLY!!! The solder dots are so close together Im already sure I will be accidentally unintentionally desoldering some things I shouldnt be. Im assuming there is no easy way to identify them when they are all this close together. Any advice for this noob as I decided this will be my first cap kit.
 
Yes, don't do it. I hate working on a board where someone did a capkit. Very seldom are they needed. And 13 electrolytics? All bad? You sure?
 
Having sound issues. Not all the sounds are happening when they are suppose to. And some fade away during game play. Its a known issue and the cap kit has made a real noticeable difference for those who have done it. Its recommended to just replace all 13 caps in the sound section of the board.

Yes, don't do it. I hate working on a board where someone did a capkit. Very seldom are they needed. And 13 electrolytics? All bad? You sure?
 
cap failure causes sounds to drop out on these, yes.

I actually did this repair on a friend's game.

his sound works again fully. I was expecting it to be a daunting task but it was incredibly easy.
 
So it was easy for you to identify what to desolder on the back of the board. The solder dots are so darn close together its hard to figure out which one is which. Do you have any tips for me. Thanks.


cap failure causes sounds to drop out on these, yes.

I actually did this repair on a friend's game.

his sound works again fully. I was expecting it to be a daunting task but it was incredibly easy.
 
I did this on a friend's Zaxxon years ago, and I don't remember it being difficult. Though if you're not comfortable soldering, let someone else do it... don't trash the board.

Advice: Feel which way the original caps easily tilt... then you know which way the legs are oriented on the board (caps easily tilt left/right when the legs are up/down... and vice versa). And if you desolder a pin you shouldn't have... just resolder it... no big deal.

Yes, don't do it. I hate working on a board where someone did a capkit. Very seldom are they needed. And 13 electrolytics? All bad? You sure?
While I'd normally agree (and definitely hate cleaning up someone else's mess), Zaxxon has a well documented common problem of sound going out after a few minutes with old caps. Simply replacing the caps seems to work, or this message suggests switching to bipolar caps and biasing the circuit: http://web.archive.org/web/20050107234714/http://home.san.rr.com/rbarnes/Arcade/fix.txt .

DogP
 
So it was easy for you to identify what to desolder on the back of the board. The solder dots are so darn close together its hard to figure out which one is which. Do you have any tips for me. Thanks.

yeah, I have this uncanny talent to figure out where components are mounted from the solder side.

honestly I think I marked dots with sharpie between each of the caps. I won't know again because I'm never taking that board out so long as I can help it. what a horrible design.

I was more concerned about the solder joints being difficult to work with cause they're so small. I was done in 20 minutes. so they couldn't have been that difficult.

I also think the polarities are marked. + signs
 
You get the hang of figuring out which things are what from the solder side with practice.

If you're not there yet, shine a bright light from the top side of the board, this should help you identify which things are what.

I also like to mark which things need to come out, particularly for ICs, where you can pretty easily pull one row off two separate parts, instead of pulling both from the correct one. I opt for a fine point dry erase marker, since it wipes off easily afterwards, but you could use a sharpie as well and clean it off with 99% alcohol. This would clean up some of the flux, too.
 
Where would I be marking dots with a fine point marker? The caps are pretty tight up against the board. Are you saying put 2 dots right where the leads of the cap go through then turn the board over and shine a light to see where the dots are on the other side? Sorry if Im misunderstanding what you are saying. Im pretty sure I will be able to figure out where to desolder each cap.


You get the hang of figuring out which things are what from the solder side with practice.

If you're not there yet, shine a bright light from the top side of the board, this should help you identify which things are what.

I also like to mark which things need to come out, particularly for ICs, where you can pretty easily pull one row off two separate parts, instead of pulling both from the correct one. I opt for a fine point dry erase marker, since it wipes off easily afterwards, but you could use a sharpie as well and clean it off with 99% alcohol. This would clean up some of the flux, too.
 
Where would I be marking dots with a fine point marker? The caps are pretty tight up against the board. Are you saying put 2 dots right where the leads of the cap go through then turn the board over and shine a light to see where the dots are on the other side? Sorry if Im misunderstanding what you are saying. Im pretty sure I will be able to figure out where to desolder each cap.

No, shine the light from the top side to aid you in locating the leads for the parts you want to remove. Touch the top of the cap, you'll be able to see the shadow of your finger on the back and locate the legs of the part. Mark the solder side with a marker.

That way, you have a guide for everything that needs to come out staring you in the face as you desolder.
 
sharpie that shit up!

IMG_2176_zpsdfe36487.jpgoriginal.jpg
 
and for the record, you are working with this pcb:

zaxxon-pcb.jpg


which has a lot more than 11-13 electrolytic caps, i see 40+ if not more on that pcb...

i don't own a zaxxon, and can't find an image online of only the audio pcb of that zaxxon set, can u take a photo of it (the entire backside of the audio pcb only)?

cuz that pcb doesn't seem difficult to work with at all. get a hakko! :)
 
Here is a link from a fellow KLOV member who did this cap kit. He included photos of the PCB that shows the area where the caps need replacing. The back side of the board is really what you need to see. The solder points are really tiny and close together.

https://forums.arcade-museum.com/showthread.php?t=71529



and for the record, you are working with this pcb:

zaxxon-pcb.jpg


which has a lot more than 11-13 electrolytic caps, i see 40+ if not more on that pcb...

i don't own a zaxxon, and can't find an image online of only the audio pcb of that zaxxon set, can u take a photo of it (the entire backside of the audio pcb only)?

cuz that pcb doesn't seem difficult to work with at all. get a hakko! :)
 
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Here is a link from a fellow KLOV member who did this cap kit. He included photos of the PCB that shows the area where the caps need replacing. The back side of the board is really what you need to see. The solder points are really tiny and close together.

Yup. Waiting on the solder-side photo of that pcb. And the photo I posted might be of a bootleg Zaxxon, not sure. Keep us posted on your progress! This is fun!
 
Yup. Waiting on the solder-side photo of that pcb. And the photo I posted might be of a bootleg Zaxxon, not sure. Keep us posted on your progress! This is fun!

I circled the area in RED that is tightly populated. This is where the 13 caps are all located and spread out. Nothing is labeled on this side of the PCB.

 
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