Mega Drive I - no Left audio channel

[MtothaJ]

All of a sudden I am no longer getting any audio in the left audio channel. I can safely eliminate it being a failure of the stereo mini jack socket on the front of the console since I have also the audio tapped from the underside of the mainboard (http://retrorgb.com/genesisaudiomod.html) and am not getting anything in the left channel that way either. Any ideas on where / how to troubleshoot?

[evildragon]

Does left audio play on the mono output?

Like, when Sonic gets two rings (as it alternates left and right).

[Lastcallhall]

Do you get left audio from the 2612?

[evildragon]

I would assume that when no left channel is heard, he isn't hearing the PSG either from the audio output.

I could be wrong though.

[Lastcallhall]

better safe than sorry. If it's a mixing issue then he can at least rule the 2612 out.

[evildragon]

Which is curious if the mono audio output in the back has both channels. Easy to test.

[Lastcallhall]

Yeah, well... shut up.

[evildragon]

I'm just all about testing the easy stuff first is all.

[Lastcallhall]

lol, no worries - I tend to over think these things. No malice intended.

[MtothaJ]

Which is curious if the mono audio output in the back has both channels. Easy to test.

The problem is that I am using a custom cable where sound input is via a 3.5mm stereo mini jack and not from the back AV port (http://www.retrogamingcables.com/seg...e-tv-lead.html). Any ideas how I can check whether the back AV port is outputting mixed audio in these circumstances?

[evildragon]

The problem is that I am using a custom cable where sound input is via a 3.5mm stereo mini jack and not from the back AV port (http://www.retrogamingcables.com/seg...e-tv-lead.html). Any ideas how I can check whether the back AV port is outputting mixed audio in these circumstances?

Since the DIN port is big enough, you should be able to connect the TV's audio input to the audio out pin and ground.

If anything, just check the headphone amps inputs and outputs..

[MtothaJ]

Since the DIN port is big enough, you should be able to connect the TV's audio input to the audio out pin and ground.

If anything, just check the headphone amps inputs and outputs..

OK, I will try to diagnose by hooking up two wires to the audio and GND on the AV connector and then attaching the cables to an RCA plug and see where that gets me. Trying to think of any games where the stereo left / right effect is used - ideally one where you can test this via an options screen. I have Sonic 1 but the ring collecting alternating sound is sometimes easy to miss.
The games I currently have availalbe: Sonic 1, MJ's Moonwalker, Alladin, Mickey Mouse World of Illusions, Ghostbusters, Road Rash, EA Hockey, EA Rugby, PGA Golf

[evildragon]

In Sonic, it's why I walk up to rings one at a time, and see if each chime plays.

[MEGADRIVE Jeroi]

Relapce audio cap, you probably have dead cap there and sound cannot go trough.

[MtothaJ]

Relapce audio cap, you probably have dead cap there and sound cannot go trough.

I have checked the caps in my machine and they all look as good as new. They are the supposedly higher quality Rubycon brand. I do not think this is where the issue lies.