HP 7925D Service Manual page 242

7925
Appendix A
Table A-II. HP 7925H Motherboard PCA-A7
Signal Distribution List (Continued)
AS
A6
Al* A2* A3 A4
TRACK
R/W A7
SIGNAL
DATA PCA MICROPROCESSOR SERVO PCA DRIVE CONTROL PCA
FOLLOWER PCA
PREAMPLIFIER MOTHERBOARD PCA
DEFINITION
PCA
PCA
COMMENTS
MNEMONIC
XA1Pl XA2P2 XA3P1
XA3P2
XA4P1 XA4P2
J1
J2 XA5P1
XA5P2
XA6Pl J1 J2 J3
IC01/1CI2 Interlock Chain Out Allin A2 B
IC02/1CI3
Interlock Chain Out A2/1n A3 15
IC03/1CI4 Interlock Chain Out A3/ln A4
16
To interlock Iqgic on Drive
Control PCA-A4.
i"CFL
To Fault Indicator PCA
IINot" Interlock Fault LE D
pin A12Jl-2.
IP "Not" I ndex Pulse B 3
To Power and Motor
C"5
IINot" Lock Door(Pack Access)
Regulator PCA pin
A9J1-47.
LSB
Least Significant Bit
16
16
(of Cylinder Address)
MR'FI..
IINot" Multiple Head To Fault Indicator PCA
Fault LED
pin A12Jl-8.
MHS
IINot" Multiple Head Sense L
N'5PS
"Not" Non-Destructive Preset D D
POS Position
V
To Power and Motor
PSF
"Not" Power Supply Failed N 14 Regulator PCA pin
A9J1-22.
RDA Read Data A F 13
ROB Read Data B 6 14
DENOTES SIGNAL SOURCE
• WHEN DSU IS INSTALLED, SLOTS A1 AND A2 CONTAIN HEAD
ALIGNMENT PCA AND I/O SECTOR PCA, RESPECTIVELY.
A-69