HP 7925D Service Manual page 238

7925 Appendix A
Table A-II. HP 7925H Motherboard peA-A?
Signal Distribution List
COMMENTS
Exits A4P1-N to DSU.
To Fault Indicator PCA
pin A12J1-6.
To Carriage Back Detector.
J3
J2
A7
MOTHERBOARD PCA
J1 XA6Pl
A6
R/W
PREAMPLI FIER
PCA
XA5P2
AS
TRACK
FOLLOWER PCA
XA5Pl J2
J1 XA4P2
A4
DRIVE CONTROL PCA
XA3P2
A3
SERVO PCA
16
XA3P1
E
XA2P2
J
A2*
MICROPROCESSOR
PCA
XA2P1 XA1P2
A1*
DATA PCA
N
XA1P1
DEFINITION
Attention
IINot" AGC Fault
"N ot" Access Ready
Automatic Gain Control
IINot" AGe Fault LED
ATT
BHSO Buffered Head Select Bit 0
BHS1 Buffered Head Select Bit 1
BHS2
Buffered Head Select Bit 2
BHS3
Buffered Head Select Bit 3
Spare
CBFC
"Not" Carriage Back Fault
LED
CBS
Carriage Back Supply
ACW AC Write (Current Sense)
AGC
ACRY
SIGNAL
MNEMONIC
DENOTES SIGNAL SOURCE
• WHEN DSU IS INSTALLED, SLOTS A1 AND A2 CONTAIN HEAD
ALIGNMENT PCA AND I/O SECTOR PCA, RESPECTIVELY.
A-65