Nintendo VS PCB Help. No Audio.

Culcuhain

Member
Joined
Aug 15, 2009
Messages
613
Reaction score
19
Location
St Paul, Texas
I just got to boards in that I knew were flaky. I am happy.
They both have no audio. Game boots up fine, plays fine. No Audio.
Audio does work with the 5 other PCBs I have (including the game I am testing with).

I have the schematics (although not too pretty) but I figure I would ask for a good starting point on the board and where/what to test and what results are good/bad. :)

Thanks guys!
 
Audio comes from the 2a03. I would:
1. Do a visual on the caps in the audio circuit.
2. Swap the 2A03
3. Put a scope on and see where the audio stops.
 
Ok,
2 other games and 4 other 2A03 chips and still no audio.
Caps look good....

Going to start tracking the voltages/signals....
 
Ok. I took a good look at the LM3900N ships...

One board has black all over the legs...

The other looks like burn marks.....

So I just ordered 25 of them from Mouser...
I like backups... :-D Thanks guys!!!
 
woot

all 25 showed up today...
and hour or so later...

2 working boards with audio and 21 spare LM3900N! (HAve 7 working pcbs nows, spares good and cheap).

Thanks guys!!!!
 
Back
Top Bottom