22" Cinema Display DVI

My 22" cinema display - the original DVI model - shows an amber light when attached to power which goes dark when an attached Mac turns on. i.e. at the moment the power light would normally go green. The screen is, of course, dark. The other symptom is that I can hear a faint, rythmical tink, tink, tink... from it at the same time.

Things I've tried, one at a time, with parts from another display with problems of its own but a picture of sorts: replace back cover w/switch, replace main board, replace inverter board, replace ADC cable, replace power supply. The graphics card in the Mac is known good.

Just thought I'd ask for input before I abandon my attempt at recycling.

Cheers,

John