Sega CD Model 2 Recapped no sound effects

[cn817166]

Took a perfectly working Sega CD V2 and recapped everything due to some leaking on about 3 of the capacitors.

 

This is a Funai C02 mainboard on a Sega CD V2.

 

Everything works fine on it except no sound effects come from the unit anymore.  CD Audio works fine, In game Background music works fine, and I've triple checked the caps, cleaned everything, laser is new and working great.

 

Anyone have an issue like this in the past?  Can't seem to find much information out there.

 

Anything that could be checked that you know of ?

 

[nick3092]

I would focus on rechecking the caps in the audio mixing circuit. Looks like 232, 233, 234, and 235 would be the most likely ones if I'm looking at the schematic right.

 

If you are using a model 1 Genesis and mixing in from the headphone jack, also check 239 and 240. 

[cn817166]

Thanks.  Will do that now.  Appreciate you.

[cn817166]

Yeah something is off.   I reflowed those caps and it's kind of working but glitchy sound a bit.  But sound effects came back kind of.    Very odd.  Maybe they are bad caps?  Weird.  Thanks for your suggestion.  

[nick3092]

The new caps being bad are somewhat unlikely, assuming you bought name brand caps (Nichicon, Panasonic, etc) from a reputable seller (mouser, digikey, console5, etc). If you bought some cheap Chinese caps from amazon or eBay or something, then it's possible.

 

The only other thing I could suggest is using a multimeter to make sure you have good continuity from each leg of the caps to wherever else they connect to. It's possible a pad was damaged in the recap and no longer making a good connection.

 

Usually you can visually follow the traces to know where to check. Or you can use the schematic to see where to check continuity. The audio mixing is all in the very bottom middle of this one. It's how I figured out which caps to recheck. 

 

[cn817166]

Thanks.   I got it much much better, it's just really scratchy sounding now, but very consistent, reflowed all of the caps.   Has to be something stupid.

[cn817166]

Took a break from it for a while.   Came back, and checked everything underneath a few more times.   After probing and checking everything on that schematic, I found one tinyyyyyyy barely even noticeable broken trace near C222 (under the board where the negative of C222's ground is) and patched it with a new trace wire and Digital Audio is back perfectly.   

I had 4 of these caps that just wouldn't budge, and took extra heat and force to remove.   Messed up but glad I found it.  Thanks a lot.  Sometimes ya just gotta take a step back and come back to it.