A forum to show appreciation and respect for classic video game systems and games. Whether you're a modder, a programmer, or just a collector, this forum is about appreciating classic games and systems in a constructive community environment.
 
HomeHome  CalendarCalendar  FAQFAQ  SearchSearch  MemberlistMemberlist  UsergroupsUsergroups  RegisterRegister  Log in  

Share | 
 

 TwinFamicom - missing audio chanel in Disk system part

View previous topic View next topic Go down 
AuthorMessage
jpx72



Posts : 3
Join date : 2013-07-12

PostSubject: TwinFamicom - missing audio chanel in Disk system part   Fri Jul 12, 2013 8:31 am

Hello, I am searching for some help around here, I bought a non working Twin Famicom (non turbo version), fixed a rather trivial fault (bad connection between the main PCB and FDS drive) and it's working again, but the guy who sold it to me was using it for some experiments so, as I found out, some of the capacitors were already exchanged, the 2C33 is socketed and there may be something else exchanged, that I cannot tell...
The problem is that the Disk system part sounds like it's missing one of the audio channels - listen to this Zelda tune recorded from it:
http://www.mediafire.com/?b1a2g330xe7gqve (mp3)
I tried to exchange the capacitors that seemed leaking, but I forgot where to put them back so I asked Drakon for help and I got this image for the right type of capacitors: http://i.imgur.com/ncXTdZk.jpg
Anyway exchanging caps for new and correct ones haven't repaired the missing channel problem.
Any idea what might be causing this? Thanks for any help!
Some detailed pictures of my board (big size):
http://www.mediafire.com/?s69s2uhx40mpljy
http://www.mediafire.com/?9rqz9yvu5bzg8la
http://www.mediafire.com/?okf44t4b13bzd4k
Back to top Go down
View user profile
Drakon
Admin
Admin
avatar

Posts : 1607
Join date : 2012-01-25
Location : Canada

PostSubject: Re: TwinFamicom - missing audio chanel in Disk system part   Fri Jul 12, 2013 9:01 am

I'm too lazy to listen. Which audio channel is missing, a fds one or a regular one?
Back to top Go down
View user profile http://16bitgamer.canadian-forum.com/
jpx72



Posts : 3
Join date : 2013-07-12

PostSubject: Re: TwinFamicom - missing audio chanel in Disk system part   Fri Jul 12, 2013 9:14 am

Well when I run the rom in FCEUX and disable the FDS audio chanel, it sounds exactly like my Twin Famicom. So I guess the FDS channel is the one missing.
Back to top Go down
View user profile
Drakon
Admin
Admin
avatar

Posts : 1607
Join date : 2012-01-25
Location : Canada

PostSubject: Re: TwinFamicom - missing audio chanel in Disk system part   Fri Jul 12, 2013 12:46 pm

jpx72 wrote:
Well when I run the rom in FCEUX and disable the FDS audio chanel, it sounds exactly like my Twin Famicom. So I guess the FDS channel is the one missing.

If you can find the pinout of the 2c33 chip see if you can find the audio out pin. Tap the pin with a capacitor and see if you get audio. If audio works from the chip you know the missing link is somewhere on the pcb. First you need to find out if the problem is the chip or the pcb.
Back to top Go down
View user profile http://16bitgamer.canadian-forum.com/
jpx72



Posts : 3
Join date : 2013-07-12

PostSubject: Re: TwinFamicom - missing audio chanel in Disk system part   Sat Jul 13, 2013 5:15 pm

Well I found the pin #54 of 2C33 that produces the FDS sound. I tried to get the audio there and it worked. So the problem is somewhere in the channel mixer. I have to trace it. Any chance of TwinFamicom schematics?
Back to top Go down
View user profile
Drakon
Admin
Admin
avatar

Posts : 1607
Join date : 2012-01-25
Location : Canada

PostSubject: Re: TwinFamicom - missing audio chanel in Disk system part   Sat Jul 13, 2013 9:43 pm

jpx72 wrote:
Well I found the pin #54 of 2C33 that produces the FDS sound. I tried to get the audio there and it worked. So the problem is somewhere in the channel mixer. I have to trace it. Any chance of TwinFamicom schematics?

Try googling but I wouldn't bother with schematics.  The twin pcb has no masking just follow the circuit and tap it at various points until you find where the audio stops.
Back to top Go down
View user profile http://16bitgamer.canadian-forum.com/
Sponsored content




PostSubject: Re: TwinFamicom - missing audio chanel in Disk system part   

Back to top Go down
 
TwinFamicom - missing audio chanel in Disk system part
View previous topic View next topic Back to top 
Page 1 of 1
 Similar topics
-
» Pre-WotLK System Requirements
» Tau Smart Missile System
» SYSTEM-OF-A-DOWN app
» CIRCULAR MOTION pres ANTHONY NICHOLSON-AUDIO SPECTRUM
» TCI Official Forum Ranking System

Permissions in this forum:You cannot reply to topics in this forum
 :: Specific Console Information And Discussions :: Nes / Famicom-
Jump to: