Modifying SNES consoles between PAL-M and NTSC is generally fairly straightforward - just swap the crystal oscillator and connect a specific pin of the video encoder chip to either +5V or GND (depending on whether you want PAL-M or NTSC).
My particular SNES Jr. is an American model, modified back in the 90s to output PAL-M video. The job was a little messier than it should, so I carefully reverted everything, soldering IC terminals back into place, removing jumper wires, and replacing the crystal for a 21.47727MHz one.
I was pretty confident everything would work right away, but to my surprise, the colors were wrong and my TVs just weren't detecting the signal as NTSC. I tried another crystal but things didn't really change.
My next step was going to be installing the missing trimmer capacitor near the crystal to see if that would be enough to correct the crystal's frequency, but it turns out that just *touching* a particular place in the board fixes everything instantly:
Simply putting one of my multimeter's leads into that little hole fixes everything - all the colors become stable, and the console outputs a beautiful NTSC image. A little piece of wire or solder (not connected to anything other than my hand) also work just fine. Can anyone explain what's going on here?
I mean, it's great that just placing a piece of metal there fixes everything, but it's not like I can simply leave a piece of wire dangling there and call that a fix... What would an actual fix be then? Any help is greatly appreciated!
My particular SNES Jr. is an American model, modified back in the 90s to output PAL-M video. The job was a little messier than it should, so I carefully reverted everything, soldering IC terminals back into place, removing jumper wires, and replacing the crystal for a 21.47727MHz one.
I was pretty confident everything would work right away, but to my surprise, the colors were wrong and my TVs just weren't detecting the signal as NTSC. I tried another crystal but things didn't really change.
My next step was going to be installing the missing trimmer capacitor near the crystal to see if that would be enough to correct the crystal's frequency, but it turns out that just *touching* a particular place in the board fixes everything instantly:
I mean, it's great that just placing a piece of metal there fixes everything, but it's not like I can simply leave a piece of wire dangling there and call that a fix... What would an actual fix be then? Any help is greatly appreciated!
Statistics: Posted by tokumaru — Tue Jan 16, 2024 8:02 pm — Replies 2 — Views 163