Greetings everyone. Hate to be making this my first post, but I've run out of ideas. I finally had the time to sit down and finish my NESRGB mod today. I very carefully followed the directions from Tim Worthington's site here: http://etim.net.au/nesrgb/installation-nes/ and methodically tested continuity on my connections throughout the build process. I had one small glitch during the process in that I slightly cracked the C24 ceramic disc capacitor while trying to remove the PPU. I ended up desoldering C24, removed the PPU then taped up the capacitor a bit and put it back in. Perhaps feeling a little overconfident, I buttoned everything back up, hooked it up to RGB on my framemeister and fired it up. Initially I had no video, but I did have audio through the scart connection into the framemeister. I proceeded to try hooking it up over composite and S-Video. Both of those worked. After maybe a minute or so, I saw some graphical artifacts on the screen in the form of vertical white dashes. I shut down removed everything and rechecked continuity on the PPU pins to the back side of the motherboard. Everything beeped except 2-9 and 14-17, which it is my understanding shouldn't have continuity to the back of the board. I loosely assembled the console and tested it again, only this time I have nothing. There's a gray screen and no audio over composite, and just blank screens over S-Video and RGB. I read the C24 capacitor as best I could and came up with this as a possible replacement: http://www.digikey.com/product-detail/en/vishay-bc-components/K103Z15Y5VF5TL2/BC1158CT-ND/286780 Does that look right? Is that even my issue or is there likely something else amiss? Here are a few pictures of my install (sadly I couldn't get embedding to work): https://goo.gl/photos/VjQVjupbpRs1Z9Eq6 <---showing the C24 capacitor https://goo.gl/photos/cFxqWCH4JWSjWmn6A <---my connections on the NESRGB board https://goo.gl/photos/QeyUUrjQDPSkf2PG7 <--- connections at the video headers https://goo.gl/photos/CjktyEDahUU9vrEv9 <---overview. I've also double and triple checked continuity from the NESRGB board to the pins on the video output headers and they all beep. Any thoughts on where I should go would be greatly appreciated. Thank you.
If you get a gray screen and no audio, the game isn't running due to a bad or dirty cartridge connection. Remember that the audio should work pretty much no matter what. If the game you are running requires no user input to hear some kind of audio but you don't hear it and you have a solid color screen, it's because the game isn't running. If your lockout chip is functional, sometimes you'll get a blinking screen (and power led) however that only happens when a small number of signal pins are dirty. There are plenty of other pins that can be dirty and cause a game to crash the CPU while the lockout chip is functioning perfectly. Your install may be just fine and all your issues may just be related to a dirty connector, dirty cartridge, or connector needing the pins tightened up a bit. You did say you got no RGB but S-Video worked so maybe you did or do have an issue somewhere in the RGB output. I'm not sure how important that cap you mentioned really is. But if it failed and you can replace it you should do so.
I got to spend a little more time tinkering with the NES again tonight. I swapped out the ceramic capacitor with an equal value one I managed to scavenge out of an old car stereo. I also installed a new 72-pin connector I had lying around. I checked continuity on a number of my connections again then reassembled and fired it up. This time composite video worked fine, but nothing on S-Video or RGB. I did get audio on everything at least. Afterward I stripped it back down and started checking continuity all the way through the line including the cables. It seems there may be an issue with pin 3 and/or pin 5 these are for sync and +5 V power. It will take a little more investigating tomorrow. Also I'm pretty stumped why the S-Video isn't working now. Continuity on the S-video checked out fine all the way through the cable. If I'm unable to get it working after hopefully going through a couple possibilities tomorrow, I think it may be time to try and get in touch with Mr. Worthington. Also, I should probably note that I modded an SNES-mini for RGB a while back and that works perfectly. So everything else about my equipment and setup is fine as far as I know. I really really want to get this working.
