SNES No Sound Output

Includes but not limited to: SNES, Genesis, Sega CD, PlayStation 1, Nintendo 64, Dreamcast, Game Gear and I guess the Virtual Boy.

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rcullan
Posts: 34
Joined: Mon Sep 21, 2009 7:16 pm

SNES No Sound Output

Post by rcullan » Sun Jan 13, 2013 1:35 pm

I am completing a project and am having an issue with my SNES...

I am using the long original motherboard with the attached sound module and I made 2 dumb mistakes. I wired up one side of the cartridge slot backwards compared to the other and the insulation on my ribbon cable nearly melted before I realized what I had done and killed the power. I rewired it correctly and tested the motherboard without the soundmodule attached and only the video to see if I had killed it or not. It worked so I finished hooking everything up and now the games play fine video and control wise but there is no sound. I have double checked all my connections there are no shorts and everything is hooked up correctly... did I fry something?

Any suggestions are really appreciated
I build rocket parts for a living... really

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rcullan
Posts: 34
Joined: Mon Sep 21, 2009 7:16 pm

Re: SNES No Sound Output

Post by rcullan » Tue Jan 15, 2013 7:32 pm

So I bought a second SNES on craigslist. And this one has the second revision motherboard with the on-board sound module, cool. It was working fine, I tested it before I opened her up (with the Multi-Out Cable). But now THIS one has no Audio too. AUGH!!!!!!!!!! Help!!!!! The video works fine, the controller works fine. I have tested multiple games just no sound. Two in a row. I dont know what the heck I did.

I have double checked and triplechecked everything. No shorts, no lose wires, frayed ends, distended caps, nothing. WHAT THE HELL!?!?!?

Here is all I did to this SNES motherboard:
1. Removed DC Power /Back Plate
2. Removed RF Modulator
3. Removed Multi Out Attachment
4. Removed 7805 Regulator (being supplied +5V from another source)
5. Removed reset switch
6. Rewired +5V from previous 7805 location to power supply
7. Rewired Ground from previous 7805 location to power supply
8. Wired AV ground to Multi-Out Pin # 5
9. Wired Video Out to Multi-Out Pin # 9
10. Wired Left Audio to Multi-Out Pin # 11
11. Wired Right Audio to Multi-Out Pin # 12

THATS IT! I didnt even move the cartridge slot. I am plugging the games directly into the motherboard. Ironically I wanted to verify everything is working prior to moving forward. Please help!

Edit: I did some more testing and I found that while running, if I disconnected my red RCA (right audio) cable from my TV the picture on the screen cut to a black and white with random white lines across it. Looked like a grounding issue. So I killed the power and tested for a short on each of the AV wires to ground. Nothing. So I am perplexed. Nothing also happens when i disconnect the other audio channel. So what could be causing this? A short somewhere else on the board? Can someone point me in a direction to look?

Also seeing as there seems to be some grounding issue I cant track down there is a single horizontal line that slowly goes from the top of the screen to the bottom and starts again that slightly distortes the pixels is going on the AV channel. I dont know where its coming from and I dont know if its related to my audio not working. But it would also make sense if there was a short and no audio signal was even making it to the AV audio pins.
I build rocket parts for a living... really

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