C257 Main Board (Stylus Color 740); Power Supply Board; C206 Psb/Pse (Stylus Color 440, 640) C257 Psb/Pse (Stylus Color 740) - Epson Stylus Color 640 Service Manual

EPSON Stylus Color 440/640/740

1.8.4 C257 Main Board (Stylus Color 740)

C257 Main board controls Stylus Color 640 and consists of following
major electric elements.
Figure 1-14. C257 Main Board Major Electric Elements
Chapter 1 Product Description

1.8.5 Power Supply Board

C206 PSB/PSE (Stylus Color 440, 640)
C257 PSB/PSE (Stylus Color 740)
In the electric boards for Stylus Color 440, 640, 740, a switching
regulator method is used and supplies stable logic and power voltages
constantly. Also, since this C206/C257 PSB board ha secondly type
switch for its circuit system, it is possible to keep supplying electricity to
the C206main-B/C255/C256/C257 main control board for 30 seconds
even after the power switch is turned off. Using this time difference,
even when mis-operation is done by the user such as turning off the
power during the middle of printing work, it prevents thickened ink from
attaching around the nozzle plate by transferring the head to cap
position.
Q1(FET)
Fuse(F1)
CN1
Filter(L1)
Figure 1-15. C206/C257 PSB/PSE Board Major Electric Elements
Revision A
C51
Trans(T1)
CN2
PC1
C11
IC51
40