RGB Problems

JeffMan · Post by **JeffMan** » Sun Mar 12, 2006 2:39 pm

Alright, here's the deal. My friend and I both have SNESp's that display off composite signals. Well, the picture sucks, so today we tried using RGB. We wired it all up and tried it. Picture works great for me, crystal clear. But we aren't getting any audio. Neither of us are getting audio, so the chances that we accidentally disconnected are slim, because neither channel works.

The only thing I can think of is this: there are two sets of audio inputs on the PSOne screen. We're using the first set right now, but I'm thinking that we might have to switch over to the other set. Perhaps the screen says "OK, there's a composite video signal, so I'll look for audio signals beside the composite input. Or, I see an RGB video signal, so I'll look for audio inputs over there.", I don't know. Any help would be appreciated.

Post by **Sparkfist** » Sun Mar 12, 2006 9:39 pm

Sounds like you haven't grounded the audio. Be sure you have the audio ground and the Right and Left wired properly.

Turbo Tax 1.0 · Post by **Turbo Tax 1.0** » Sun Mar 12, 2006 10:03 pm

and you have 5 volts going to the input and output of the 7805 leads on the snes

JeffMan · Post by **JeffMan** » Mon Mar 13, 2006 10:00 am

The audio was working fine before the RGB switch though...
Turbo: yeah, we did that.

I'm going back at lunch today to work on it. I'll try the other audio inputs on the screen, and then I'll try grounding the audio or whatever.

JeffMan · Post by **JeffMan** » Mon Mar 13, 2006 4:22 pm

Alright, just an update... my theory was correct, we were using the wrong audio inputs for the screen. Mine works great now, sound and everything. But I think my friend's SNESp might be royally screwed. It wasn't working at all today, so we decided to go in and check why. We couldn't figure anything out, neither the screen nor the SNES were turning on. So I thought maybe the power might be shorting. I checked it with a multimeter, and his +5V and ground on his SNES are shorting :X

Are there any blatantly obvious places that we should check for the short? We're checked all around the 7805 and stuff, and theres a big mess underneath the AV plug, but we're sure that nothing's shorting there.

SNESguy · Post by **SNESguy** » Mon Mar 13, 2006 6:18 pm

If something's shorted, it's most likely due to a foreign object on the motherboard.

So,
Check the motherboard for any stray blobs of solder you may have dropped while making the portable. I recommend using a clean paintbrush and "dusting" off the motherboard.

Stray Solder blobs are the most likely reason for a short. Good luck.

SNESguy

timmeh87 · Post by **timmeh87** » Mon Mar 13, 2006 9:09 pm

random thought:

if you had a really sensitive digital multimeter (something that can do miliohms, maybe micro-ohms), you could check the resistance between +5 and ground at various points. the lower the resistance, the closer you are to the short. you might be able to zero in on it like that... never tried it though.

Turbo Tax 1.0 · Post by **Turbo Tax 1.0** » Mon Mar 13, 2006 9:24 pm

i had a problem like this it was on a mini though but you could probably fix it the same way. i know on the mini there was a little black almost boxlike surface mount thing with 4 pins, that was next to the big white fuse. turns out somehow i fried this thing and it combined my 5 volt line and ground together. all i did was remove it and i was fine

but make sure you still have power going into the output lead on the snes where the 7805 used to be