Tektronix 371B, Service Manual

Page: 97 / 292

Maintenance
371B Service Manual
4-25
4. Remove the four spacers that secure the A18 board to the chassis and lift the
A18 board from the main unit.
5. Replace the A18 CRT Output board in the reverse order of removal.
A20 High Voltage (H.V.) Regulator Circuit Board.
Perform the following to remove
and install the A20 H. V. Regulator board.
1. Remove the left side panel from the 371B.
The CRT anode circuit retains a charge of up to 12000 V. Be sure that
the circuit is completely grounded to the chassis before handling the circuit
board, otherwise, serious injury or death may result.
2. Remove four screws that secure the shield over the A20 H.V. Regulator
board. Set the shield aside.
3. Remove the screw that holds the retainer clip for Q100 to the chassis.
4. Remove the CRT anode cap from the jack located on the left side of the
CRT. Ground the CRT anode cap to the chassis to discharge any stored
charge.
5. Remove J182, J194, and J200 from the A20 H.V. Regulator board.
6. Remove the four screws that secure the A20 H.V. Regulator board to the
chassis, and remove the board from the main unit.
7. Replace the A20 H.V. Regulator board in the reverse order of removal.
A22 Interface Board.
Perform the following to remove and install the A22
Interface board.
1. Remove the top and rear panels from the 371B.
2. Remove J220 from the A1 Mother board. Refer to the “A2, A3, A4, and A5
Plug-In Circuit board” removal procedure.
3. Remove the four screws that secure the IEEE STD 488 port connector and
PRINTER INTERFACE port connectors to the rear panel.
4. Remove four screws that secure the A22 Interface board and lift the board
with its insulation cover away from the rear panel.
5. Replace the A22 Interface board in the reverse order of removal.