HP 7475A Service Manual page 38

Model 7475A
Section V
ITEM3
Date code 2420-11 introduced a design change that eliminated inductive voltage spikes in the motor drivers when the
plotter was switched off. The part numbers that differ from those listed in Section IV; and the effect of these component
differences on the schematic diagram and parts location figure in Section VI, are as follows:
REFERENCE
DESIGNATOR
AlDSl-2
A1DS3
A1E4
A1E8
AlEll-16
A1E18-20
A1H3-6
A1H9-12
A1J4
A1U28
+svl
7475-8-37-2
MAIN PCA, RS-232-C, OPTION 001
PART
NUMBER
DESCRIPTION
1990-0485
LED
1990-0487
LED
1200-0567
SOCKET
1200-0654
SOCKET
2110-0597
FUSEHOLDER
07470-40038
SPACER
0515-0055
SCREW
0535-0031
NUT
1251-4946
CONNECTOR
07475-60103
DIODEAY
~
I
1+18/26V
"'"
PEN COIL
SUPPLY
DS2
1'
>--'..;;_ _ _ _
__,.,.,.~-1--1.....i-~v
•PART OF U28
DIODE ASSEMBLY
07475-60103
Ri3
3.
16K
R2
IK
PAPER SIZE
(gj
OSI
1t
>--''-'--~,,.,..__-~I-+--
+5V I
I
- - - - :A:ER SIZE
[ill'
CHECK
DIGIT
CAROUSEL
DRIVE
STEPPER
MOTOR
5
7
1
7
7
6
8
2
5
3
Partial View ofRS-232-C Main PCA Option 001 Schematic Diagram (Date Code 2420-11)
7475-A-2&-2
Partial View ofRS-232-C Main PCA Option 001 Parts Location Diagram (Date Code 2420-11)
5-3