I've been building a good Mystic Colour Classic out of two flaky ones ...
- One in perfect physical nick but seemingly had the Mystic mod attempted, and failed. Chimes and boots but no video
- Another CC sprayed black with successful Mystic mod *but* sound chip removed! Has yellow tint on screen.
So, I desoldered the sound chip off the better one and got the "good" Mystic AB working, in the good condition case, sound and VGA video working.
Now it's all going a treat but it the yellow tint still remains. Adjusting the green or red pots on the AB (for drive and background respectively) elicits a change in hue but adjusting blue drive does nothing - no perceptible change.
I've resoldered the PCB at the back of the yoke to no avail - which leaves me with the AB - could there be a cold solder joint somewhere, where should I look/start?