DC or AC instruments?

The complete loss of AC electrical power, said NTSB investigators, would have rendered most of the pilot's flight instruments inoperative. The only instruments that would have been available to the pilot were those that were operated by the pitot static or vacuum systems. On the left side of the cockpit, only the airspeed indicator and the turn and slip indicator would have been operational. On the right side of the cockpit, the airspeed indicator, turn and slip indicator, altimeter and attitude indicator would have been operational. Despite the loss of the airplane's primary flight instruments, the pilot made no radio transmissions to the controller after Mode C information was lost. (Between one minute, 33 seconds and one minute, 36 seconds elapsed between the time of the last Mode C return and airplane impact.) The airplane's air data computer also produces electrical output signals for the autopilot. Thus, the complete loss of AC power would have caused the autopilot to cease operating if it were being used.

IASA