C524Main Board - Epson 890N - FX B/W Dot-matrix Printer Service Manual

EPSON FX-890/2190

4.2.3 C524MAIN Board

The C524MAIN board has the mechanical drive power supply
voltage (+42V, Vp) management circuit and an electrical
characteristic of the components composed of this circuit is
measured with the custom instruments and regulated at the
assembly process. Never attempt to replace any components of
this circuit on the board, and doing so resulted in damaging the
unit.
Be careful with the edges of the shield plate, as they are very
sharp.
Be sure to match the connector colors with each other.
1. Perform Pre-Disassembly. (p.70)
2. Remove the Upper Housing. (p.72)
3. Remove 5 CBS (M3x6) screws and 2 CBP (M3x12) screws securing the shield
cover to the Printer Mechanism and lower housing. Then remove the shield cover.
(See Figure 4-8)
4. Disconnect all the connectors connected to the C524MAIN board.
(See Figure 4-9)
CN No. Pins Color
CN5 2 Blue
CN6 2 Black
CN7 3 White
CN8 2 White
CN11 2 Yellow
CN12 5 Red
CN13 4 White
CN14 10 -
CN15 (FPC)
CN16 (FPC)
CN19 2 White
CN20 (FPC)
Disassembly and Assembly
Table 4-4.
Connected to
PG Detector
Front PE Detector
Rear PE Detector
HP Detector
Release Detector
CR Motor
PF Motor
C524PSB/PSE/PSH Board
Printhead
Printhead
Fan
Panel
Main Components Disassembly
CBP Screws (3x12) x2
Tightening Torque
: 0.78-0.98 N.m
No screw here
(Screw for tightening the
Upper Housing together
must be installed later)
Figure 4-8. C524MAIN Board Removal 1
Figure 4-9. C524MAIN Board Removal 2
Revision B
CBS Screws (3x6) x5
Tightening Torque: 0.58-0.78 N.m
Shield Cover
74