I recently got hold of an Apple 21 inch studio display that had been dumped because it had failed.
When the monitor is connected to an apple and powered up, it remains in sleep mode, (the small lamp at the front remains orange suggesting the monitor thinks it should be sleeping).
After removing the funky plastic enclosure I have found the circuit board that seems to control the monitors operation and sleep function.
Is there anybody out there who has had experience of the mode of failure and the most likely culprit on the circuit board...many thanks