Avery Berkel CX20 SERIES, Service Manual

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11 — Main PCB
11–10 CX20/CX30/CX34 Service Manual
11.2.3 Removing the main PCB (CX20 W)
To remove the main PCB on the CX20 W, proceed as follows:
1 Make back–up of unit data (refer to Part 2, Programming Handbook for
use of the DCU).
2 Switch off machine and isolate it from the mains power supply.
3 Remove case (refer to Section 3).
4 Switch off battery on main PCB (DIL switch SW4, Bit 4 to OFF (0)).
Accessible in printer compartment, through hole in printer spine.
5 If main PCB is to be changed for new part, remove display and display
brackets (refer to Section 12).
6 Remove two clamps attaching main PCB to four chassis pillars by
removing four special nuts.
7 Lift main PCB as necessary to gain access for following operations:
avoid any strain to connecting cables during these operations.
8 Disconnect all cables attached to main PCB (refer to Figure 11.1)
except four–wire cable assembly (attached to A/D PCB which is
mounted on component side of main PCB) and keyboard loom.
9 Detach A/D PCB from main PCB by compressing barb on each of four
plastic clips between A/D PCB and main PCB: pull A/D PCB away in
straight direction, to avoid causing damage to PCB mounted electrical
connectors.
10 Lift main PCB away from unit.
11.2.4 Fitting the main PCB (CX20 W)
To fit main PCB to the CX20 W, proceed as follows:
1 Attach A/D PCB to main PCB by fitting it over interfacing electrical
connector and over four plastic clips between A/D PCB and main PCB:
check that barb on each plastic clip engages correctly.
2 Connect all cables attaching to PCB (refer to Figure 11.1 and
Table 11.1). Connecting cables will vary according to model and
specification of individual machine. Note that transducer cable is routed
behind rear left–hand pillar (main PCB support pillar).
3 Position main PCB approximately in correct position over unit, and
check that it aligns over overload stops (two on chassis pillars, and two
on printer spine).
4 Settle main PCB in position over transducer and four chassis pillars:
check that cables are not trapped or under any mechanical strain.
5 Fit two clamps over main PCB and four chassis pillars and secure by
fitting four special nuts to pillars (chamfer on special nuts face down, to
match holes in main PCB). Take care not to move stop bolts set in
head of chassis pillars: if moved, refer to Section 7.
6 CX20 only: if removed, fit displays and display mounting clips (refer to
Section 7).