HP 7925D Service Manual page 124

7925
Troubleshooting
Table 4-4. Motherboard PCA-A7 Signal Distribution List
(Continued)
SIGNAL
MNEMONIC
DEFINmON
A1
HEAD
ALIGNMENT PCA
A2
I/O SECTOR PCA
A3
SERVO PCA
A4
DRIVE CONTROL PCA
AS
TRACK
FOLLOWER PCA
A6
RIW
PREAMPLIFIER PCA
A7
MOTHERBOARD PCA COMMENTS
XA1P1 XA1P2 XA2P1 XA2P2
J1 XA3P1 XA3P2 XA4P1 XA4P2 J1 J2 XASP1 XASP2 XA6P1 J1 J2 J3
ICA Illegal Cylinder Address
6
ICIS
Interlock Chain In AS
17
Interlock chain source from - 24V supply.
ICOS/lCI6
IC06
ICI2
Interlock Chain Out ASlin A6
Interlock Chain Out A6
Interlock Chain in A2
14
15
To pack chamber interlock pin J2-7.
From Spi ndle Logic PCA pin A8P1- T.
IC02/1CI3 Interlock Chain Out A2/ln A3
15
IC03/ICI4 Interlock Chain Out A3/ In A4
To interlock logic on Drive Control PCA
16
-A4.
ILFL "Not" Interlock Fault LED
To Fault Indicator PCA pin A12J1-2.
IP "Not" Index Pulse
B 3
LD "Not" Lock Door (Pack Access) To Power and Motor Regulator PCA pin
A9J1-47.
LSB
Least Significant Bit
(of Cylinder Address) 16
MHFL "Not" Multiple Head Fault LED To Fault Indicator PCA pin A12J1-8.
MHS "Not" Multiple Head Sense
L
NDPS
"Not" Non-Destructive Preset
0 0
POS Position
V
DENOTES SIGNAL SOURCE DENOTES BIDIRECTIONAL SIGNAL
4-57