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NEC TG-16/TE/TurboDuo => TG/PCE Repair/Mod Discussion => Topic started by: Keith Courage on April 05, 2011, 05:39:35 AM

Title: Quiet ADPCM on a Turbo DUO
Post by: Keith Courage on April 05, 2011, 05:39:35 AM

Anyone know which capacitors are for the ADPCM sound on a Turbo duo? Everything else works just fine. No other audio issues. The voices in the CD games are just way more quiet that they should be. Also, those games that have adpcm drums are barely audible as well.

Title: Re: Quiet ADPCM on a Turbo DUO
Post by: BlueBMW on April 05, 2011, 02:21:24 PM

If you're inside a duo to do caps... you may as well do them all.  Doing a few at a time is just asking for more repair work down the road. :D

Title: Re: Quiet ADPCM on a Turbo DUO
Post by: Keith Courage on April 06, 2011, 02:49:45 PM

Okay, well I just changed out all the following capacitors circled in red and the ADPCM sound is still way too quiet. I know it is normally slightly softer than music in the games but this is barely audible. Anyone have any suggestions? (http://img576.imageshack.us/img576/356/pcengineduototalcaprepl.jpg) (http://img576.imageshack.us/i/pcengineduototalcaprepl.jpg/)

Title: Re: Quiet ADPCM on a Turbo DUO
Post by: Opethian on April 06, 2011, 05:53:39 PM

yea only 36 more to go :D

Title: Re: Quiet ADPCM on a Turbo DUO
Post by: BlueBMW on April 06, 2011, 06:26:22 PM

Yep, just get in the habit of changing them all.  Some of the systems are interconnected so a failure in one part of the system will cause trouble in others.

I know it sucks, but just do all the caps.  It wont take that long :D

Title: Re: Quiet ADPCM on a Turbo DUO
Post by: Charlie on April 06, 2011, 07:38:57 PM

Try "http://www.pcenginefx.com/forums/index.php?topic=7328.0"

Also note that the technical explanation there (and in the linked thread) may be a bit out of date, but the abbreviated schematic should be 100%.

Charlie

Title: Re: Quiet ADPCM on a Turbo DUO
Post by: nat on April 08, 2011, 02:40:33 PM

Also: did you clean the board at the time you changed the caps? If not, the conductive electrolytic goo is still there, possible shorting something out.

Title: Re: Quiet ADPCM on a Turbo DUO
Post by: Keith Courage on April 08, 2011, 05:14:20 PM

I found the problem. None of the caps were bad. Turns out one of the really small resisters on the board went bad. All I had to do was bypass the adpcm audio to the next resister in line. I'll post a picture of what I had to do to fix the issue when I get the chance.