HRT-210B Rotary Table Issue

We have a 2004 VF5 with a HRT-210B rotary table, and are currently experiencing an alarm indicating an overload condition with the HRT-210B.Load meter is reading a 200% load when trying to rotate the part.

I assumed it was probably an issue with the pneumatic brake, but after getting into the disassembly of the unit to do some troubleshooting, I first noticed a rust colored "dust" on the drive belt & motor mount bracket. I'm not sure how to properly bench test the servo motor, but it is very difficult to rotate the motor shaft/drive belt pulley.......is this normal, or should it rotate freely?

As long as I'm asking questions, I'm having a hard time getting my head around how the brake is applied. I understand that it is pneumatically actuated, but as I said I'm having trouble seeing how the brake disk is applied/released.

Any input would be appreciated.

Thanks, Dave

Air applies and air releases the brake. With brake off input shaft should turn without too much effort.

Servo should turn by hand easily with power off.

I just went through one that had the air solenoid die. The belt partially broke as it tried to force against the brake. Solenoid and belt were about $220 combined online.