Maintenance
8500C/8500C+ System Maintenance Manual
A-23
A.4.7
8520C-36 Disassembly (Figure A-10)
A.4.7.1 Controller Board A3
a.
Turn unit upside down, remove eighteen screws (3) and washers (7), and remove bottom
cover (12).
b.
Disconnect four connectors (J1, J2, J3, P2) from controller board A3.
c.
Remove five screws (5) and nylon washers (30), one screw (29), nylon washer (30), cable
clamp (31), and shoulder washer (4). Remove controller board A3 from chassis (11).
A.4.7.2 Mux Board A4
a.
Remove six spacers (9) and flat washers (30) from Mux board A4.
b.
Lift Mux board A4 and disconnect four connectors (J1, J2, J3, J4) from Mux board.
c.
Remove Mux board from chassis (11).
A.4.7.3 Connector Boards A1
a.
Remove forty-eight screws (3) and discard. Remove eight nut rings (26, 27) and four
connector boards A1.
NOTE: Nut ring (25) remains attached to connector board.
A.4.7.4 Dual Filter Assy. and Cable Harnesses
a.
Remove four screws (3) and washers (7) from filter (2) and eight screws (3) from
OUTPUT and DC POWER connectors/harness.
A.4.7.5 Power Supply Board A2
a.
Disconnect three connectors (J1, J2, J3) from power supply board A2.
b.
Remove four nuts (6) and two spacers (9), and remove power supply board A2 from
chassis (11).
A.4.8
8520C-36 Reassembly (Figure A-10 and Figure A-11)
A.4.8.1 Power Supply Board A2
a.
Install power supply board A2 on chassis (11) and secure with four 4-40 nylon lock nuts
and two #4 1/4” o.d. spacers (9).
b.
Connect three connectors (J1, J2, J3) to power supply board.