CPS1 Digital AV mod - Audio issue - No Sound Effects

[Dlang6487]

Hey arcade enthusiasts,
I recently installed a CPS1 Digital AV on my CPS1 Dash board along with the CPS1 Multi by Darksoft. I flashed the firmware fine as well. The video looks clear, the soundtrack music is clear, but I'm missing sound effects over HDMI. The sound effects are present over analog, so I'm looking for a little help. Where should I start for troubleshooting? I replaced the wires between the CPS2 Digital AV board and the CPS1 A board that connects BCK, DAT and WS and it didn't make a difference. Thank you ahead of time!

 

[mathewbeall]

Can you post a good high resolution picture of the digital AV board? I had this issue - for me, it turned out to be a broken trace.

Matt

 

[Dlang6487]

That's a good idea to check out! I got so wrapped up in the A board I didn't think about the adapter board itself! Here is my adapter board installed. Where was your broken trace? Thanks again!

 

[Dlang6487]

Another view of Digital AV Board.
If you remember, where was the broken trace? I'd be willing to trace it back if i knew where to start. Thanks!

 

[GoldenGlover]

I wonder if the lack of solder fill on the bottom (top?) component pins located at J1 and J2 in your first two pictures might be behind your woes? Might be a good idea to try adding some solder to those areas to make a better connection.

 

[Dlang6487]

I wonder if the lack of solder fill on the bottom (top?) component pins located at J1 and J2 in your first two pictures might be behind your woes? Might be a good idea to try adding some solder to those areas to make a better connection.

I reflowed them and still nothing. Thank you for the suggestion though! Anything helps!

 

[mathewbeall]

This ended up being my issue - can you check continuity between these points - on my board, i must have messed it up - so @ShootTheCore ran a bodge wire.

 

[ShootTheCore]

This ended up being my issue - can you check continuity between these points - on my board, i must have messed it up - so @ShootTheCore ran a bodge wire.

Here's my notes from when I probed out the digital audio circuit with my osciloscope on @mathewbeall 's board. You'll want to use a logic probe or oscilloscope to probe these pins and see if you get matching behavior. Any missing signals indicate a broken connection somewhere.

WM8782 chip on CPS1 Adapter
Pin 1 MCLK – steady clock pulses
Pin 2 DOUT– scope signals pulses only when audio is playing (digital audio output pin)
Pin 3 LRCLK – steady clock pulses
Pin 4, 8, 11, 14, 20 - Ground
Pin 5 DVDD – 3.3V supply
Pin 6 BCLK – steady clock pulses
Pin 13 AVDD – 5.0V supply

74LVC112 chip on CPS1 Adapter
Pin 1 – steady clock pulses
Pin 2, 3, 4, 10, 15, 16 – 3.3V supply
Pin 5 – steady clock pulses
Pin 8, 11, 12, 13, 14 - Ground

CPS1 Adapter Board Connections
DAO = Common Analogue Input (Coax cabled)
oCM = Audio System Master Clock (Coax cabled) 3.57955 Mhz
oC1 = Audio Interface Bit Clock (for synchronization) 3.57958 Mhz
SH1 = 74LVC112 Flip-Flop Clock Input 111.881 kHz
SO = Digital Output
3v3 = Voltage supply for 74LVC112 Flip-Flop

74LVC112 Flip-Flop’s only function is provide the ADC data alignment clock – derived from SH1.



CPS2 HDMI PCB Connections
Video
GND = Ground
C1 = Clock 16 Mhz
C2 = Clock
VS = Vertical Sync (Repurposed to Digital Input from CPS1 Adapter DAC)
HS = Horizontal Sync

Audio
GND = Ground
BCK = Audio DAC Clock 1.78978 Mhz
WS = Sample and Hold 55.9307 KHz
DAT = Serial Output 223.728 kHz

Jumpers
J3 = Should always be bridged
J5 = Should always be bridged
J6 = Should always be bridged

 

[Dlang6487]

That was it! Reflowed the solder joints on the adapter board at the point of the bodge wire and now they work great! I must have had a cold solder joint there. I can't thank everyone enough! And the info posted by @ShootTheCore is super helpful if anyone else needs to troubleshoot. I appreciate everyone's help!

 

[raynex]

Just a reminder the Q sound games won't output audio through HDMI, in case you see that later on. You'll have to use the RCA ports for that portion for now. I used an Audio Injector to make it all work through the HDMI cable. Works well for now but hoping for a combined solution one day.