The Sony BVM D9H and D14H series monitors, don’t have a built in “VCR Mode”, which results in a “sync curl” at the top of the screen. Martin, creator of the BVM replacement cards has discovered a fix for SMS consoles (demonstrated by Chris Valdez above), however PC Engine / TG-16 consoles still have the problem. At the moment, we haven’t found a way to save these settings, meaning you’ll need to make these changes every time you use your SMS. I’ll update this post as more info comes in, but this might be a great stepping stone to a permanent fix!
129x Replacement Board: https://www.retrorgb.com/testing-the-bkm-129x-replacement-board.html
129x Dual Replacement Card: https://www.retrorgb.com/dual-input-scart-vga-card-for-sony-l-series-pvms.html
BKM-68x Replacement Card: https://www.retrorgb.com/reverse-engineered-bkm-68x.html
…and if you’d like to hear more from Martin, check out our interview below!:
OK, so no need to keep any secrets, so here's a way to make at least Master System sync fine on a D9 (and most likely D14): Go to the Service menu (pass: 53415), set "H SYNC SEP1" to 0, "CLP P DLY" to 254 (or whereever colors become good).
— Martin Hejnfelt (@MartinHejnfelt) June 19, 2022