heuser.marcus@freenet.de schrieb:
See, I collected lots of crystals over the years and found two with the right frequency which I then put into the board (...) They didn't work. Maybe they were broken, but I salvaged them from old but working hardware...
The color burst frequency is critical, it must not be more than 10ppm off spec. NTSC is more forgiving than PAL, but nevertheless you will have to adjust the capacitor trimmer close to the crystal to get the right frequency.
(Or try crystals until you find one that matches your current capacitor settings :-)
The variable capacitor close to the crystal adjusts frequency, the other one ("color trim") the phase ("hue") of the burst.
Patrick