Power Supply Board Analog Input Board
DSP Logic BoardCPU Board
CAUTION
Always disconnect the power cord and
wait at least one minute before open-
ing the unit. Dangerous power supply
voltages may be present even after the
unit has been unplugged.
Check the LED at the front edge of the
power supply board. The unit is safe
only if the LED is OFF. If the LED is
ON, then DO NOT attempt any service
on the unit.
This unit is to be serviced by qualified
service personnel only. There are no
user serviceable parts inside.
VIDEO DRIVER AND CRT
Potentially lethal voltages are present
in this circuit. Do not attempt to ser-
vice the CRT and Video Driver Board.
Refer any service problems to the
factory.
CIRCUIT BOARDS
The SR850 has four main printed circuit boards.
The four boards shown contain most of the active
circuitry of the unit. The CRT and video driver
board are mounted inside the CRT shield assem-
bly. The front panel circuit board only has keypad
contacts printed on it and holds no active compo-
nents. The rear panel circuit board only provides
connections to the BNC connectors on the rear
panel.