Service manual

Epson Stylus Photo PX650/TX650/TX659/PX660/PX660 Premium/Artisan 635 Revision C
ADJUSTMENT PG Adjustment 120
Confidential
5.3 PG Adjustment
Described below is the platen gap (PG) adjustment.
 Purpose:
Adjust the distance between the head surface and the Front Paper Guide Assy
(platen) properly and adjust the parallelism on the 0-digit side and on the 80-digit
side to ensure reliable print quality.
Once the CR Unit and/or Adjustment Bushes have been removed or whenever
necessary for any other reason, make this adjustment to correct the deviation of the
platen gap.
 Things to be used
 Thickness gauge: 1.15 mm (x2)
1.3 mm (x2)
 Phillips screwdriver
Figure 5-8. PG Position at PG Adjustment
Table 5-5. PG Positions
Position
PG Size
(mm)
Application for Printing
(selected from PG flag list for
normal/head rubbing)
Sequence
Application
PG-
<APG Home>
1.2
EPSON special thick paper
PGPP, Postcards, Matte, etc.
Cleaning
CR measurement,
VH detection
CR home position
seek
PG typ.
<Mechanical
default>
1.7
Plain paper
EPSON special thin paper, SF, etc.
Rubbing with PG1.2 is avoided
PG+ 2.35
Envelopes
Rubbing with PG1.2 and 1.7 is avoided
PG++ 4.2 CD-R printing At ink replacement
C A U T I O N
 The thickness gauge to be used must be free from dust and dirt
and from deformation. Be sure to clean it before use.
 Take care that the Printhead is not soiled or scratched.
 To ensure high accuracy of adjustment, install new ink
cartridges in the carriage, and move the carriage right and left
by pulling the belt without holding the carriage.
C H E C K
P O I N T
 Make this adjustment after installing the mechanism unit in the
Lower Housing. (Install the Linear Scale after adjustment.)
Refer to "4.4.3 Printer Mechanism" (p.88)
 With Epson Stylus Photo PX650/TX650/TX659/PX660, four
stages of PG setting are available by means of the APG
Mechanism. However, make this adjustment with the
mechanism in the minimum PG position (PG-: 1.2 mm).
(Refer to "4.4.8 APG Unit" (p.95) and below.)
Locating hole
Locating hole