Apple Studio Display LCD brightness control software

I wish it was that simple.

The USB from the Apple DVI to ADC adaptor is plugged in, and the mouse and keyboard work off of the display.

It doesn't matter if I plug it into a USB1/2 port.. still not working.

It seems that it is known, but seen as not connected even though it is online:

ATI Radeon 8500:

Chipset Model: ATY,R200

Type: Display

Bus: AGP

Slot: SLOT-A

VRAM (Total): 64 MB

Vendor: ATI (0x1002)

Device ID: 0x514c

Revision ID: 0x0000

ROM Revision: 113-85710-123

Displays:

Apple Studio Display:

Display Type: LCD

Resolution: 1024 x 768

Depth: 32-bit Color

Built-In: Yes

Core Image: Not Supported

Main Display: Yes

Mirror: Off

Online: Yes

Quartz Extreme: Supported

Display:

Status: No display connected

This is a legacy system that I use with my UMAX Mirage IIse. I'll clone the system and try a combined update to 10.4.11 next. I know there was reason I didn't upgrade the OS, but don't remeber what the incompatibility was in the past.

I've done it before, and I just tried it again. I hooked it up to my MBP Early 2011 via DisplayPort>DVI adaptor and the same result. The proximity sensor lights up but no control panel is opened. The brightness controll is absent in the Monitors control panel, and a mouse and keyboard still work. The display is correctly identified in the control panel as well.

I'm beginning to think the problem might be in the display itself. 😟