Hi, all! Long-time lurker, first-time poster here. I wasn't sure if this needed to go in here or the Newbie Help forum, so I apologize if it's in the wrong place. I also checked about three years' worth of old posts with no results, so here I am!
I recently took the plunge and went all-in on RGB. SNES and Genesis are sexy in RGB, and I purchased an AV Famicom to mod. Aside from an issue desoldering the PPU (which I replaced with an intact one from a broken NES at the store I work at) and a few traces on the Fami board that a friend had to repair because I got a bit happy with my desoldering iron, I had no issues installing the mod, or so I thought.
Basically, I can't get any kind of RGB output with a known-working SCART cable. My OSSC just does not see a signal from the thing, so I'm in need of some help.
If I try to run it over a SNES composite cable with the board installed I get a picture that looks like the normal game but it's white. Not a brightness-level white, like a monochrome white with no black in the picture. Unfortunately I'm not in a place where I can take a picture of how it looks, but If I take the PPU out of the RGB board and put it back into the Fami board it works just fine over composite.
-- Jumper J8 is open because I'd like to use TTL cables instead of 75ohm (so I can use the same cables as my 2-chip SNES)
-- J3 and J5 are properly shorted for Power and NTSC.
-- I'm using CS# as my video out, because again I'd like to use the same cables as my SNES. I did try outputting through V with no luck.
-- 3 and GND are jumped because I'd like to use the default palette.
-- I didn't cut the video trace on the bottom so I could switch between RGB and Composite as needed.
-- I did already check the voltage regulator just in case I had one of the faulty ones, it's fine.
-- I used a multimeter to check continuity of the ppu to the output pins, they checked out fine. Same with the wires from the rgb board to the video out pins on the Fami board.
Here are pictures of the board and my wiring.
Thanks to all who took time to read this. Help is much appreciated!
I recently took the plunge and went all-in on RGB. SNES and Genesis are sexy in RGB, and I purchased an AV Famicom to mod. Aside from an issue desoldering the PPU (which I replaced with an intact one from a broken NES at the store I work at) and a few traces on the Fami board that a friend had to repair because I got a bit happy with my desoldering iron, I had no issues installing the mod, or so I thought.
Basically, I can't get any kind of RGB output with a known-working SCART cable. My OSSC just does not see a signal from the thing, so I'm in need of some help.
If I try to run it over a SNES composite cable with the board installed I get a picture that looks like the normal game but it's white. Not a brightness-level white, like a monochrome white with no black in the picture. Unfortunately I'm not in a place where I can take a picture of how it looks, but If I take the PPU out of the RGB board and put it back into the Fami board it works just fine over composite.
-- Jumper J8 is open because I'd like to use TTL cables instead of 75ohm (so I can use the same cables as my 2-chip SNES)
-- J3 and J5 are properly shorted for Power and NTSC.
-- I'm using CS# as my video out, because again I'd like to use the same cables as my SNES. I did try outputting through V with no luck.
-- 3 and GND are jumped because I'd like to use the default palette.
-- I didn't cut the video trace on the bottom so I could switch between RGB and Composite as needed.
-- I did already check the voltage regulator just in case I had one of the faulty ones, it's fine.
-- I used a multimeter to check continuity of the ppu to the output pins, they checked out fine. Same with the wires from the rgb board to the video out pins on the Fami board.
Here are pictures of the board and my wiring.
Thanks to all who took time to read this. Help is much appreciated!