Correction to my earlier post (too late to edit).
Of course my adapter is DVI+USB+Power to ADC, not VGA.
One hazard with the Studio Displays, as they age, is that the control chips inside the display unit can start to dement. Often the extended USB ports and the remote power switch fail, and also the ability to control brightness etc via the ADC data path. All these functions use a single data channel on ADC, so perhaps it was a bit of over-design. You can have a good quality visual display but reduced control over it, and without the ability to daisy-chain the keyboard/mouse through it. This is a pity , since the design intention was to deliver a clean desktop with only a single ADC cable to the tower under the desk.
If you've got one with all those functions working for $5, you've really cracked the jackpot.
Rick