Table of Contents
Advertisement
Rd Ctrl
Rd/Wr Call
A
D
Time
Rd Set
©
©
Wr Ctrl
©
YHi
SAR Bits
1
2
34 56
8K-16K BSM
EfSM Selection
Byte
XXG2
Control
XXH2
(not used
XXH2
24K-32K BSM
Segment Selection
on 8K)
XXJ2
SR061
ALDPage -
SR062
SR063
SR064
Figure 4-3. X or Y Drive System
4. 1.2.2 Multiple Bits, Multiple Address Failures
If this type of failure cannot be corrected by card swapping
or replacement, an array fault probably exists. If the failure
is related to a combination of more than one address pat-
tern, suspect a short between drive lines.
4.1.2.2.1 Continuity Ozeckof XY Drive Lines: The charts
on SR174 and SR184 (8K or 16K BSM) or SR234 and
(32K BSM) describe all X- and Y-drive lines and contain all
the points (terminals) for performing a continuity check.
The following example and section 4.1.2.2.2 refer to an
8K or 16K BSM, which uses Figure 4-4 and the charts
4-4
Rd Hi
Y Hi Decode (SAR 3, 4, 5, 6)
0
Y Rd Current Sink
Control
Driver
Y Rd Hi
Y Rd Lo
X Rd Hi
©
X Rd Lo
Array
YWrHi
0
YWr Lo
XWrHi
©
XWr Lo
Rd Lo
D
Y Rd Current Source
Y-Lo Decode (SAR 7, 8, 9)
©
CD
©
©
©
Gate-Driver Location
X-Y Gate
X-Y Rd/Wr
Y Lo
XHi
XHiB
X Lo
Control
Drive Current
789
10
11
12
13 14 15 Driver
Source
XXF2
XXE2
Not
XXB2
XXJ2
Used
XXD2
XXG2
XXF2
XXE2
XXC2
XXK2
SR051
SR041
SR043
SR031
SR021
SR022
SR052
SR042
SR044
SR032
found on SRI 74 and 184. (For a 32K BSM, use charts
found on SR234 and 244.)
Example:
This example is for the failing X-address of
000110 in an 8K or 16K BSM. X-read current is shown
from left to right through the array X-winding. X-write
current is shown from right to left through the same array
X-winding.
(In the following discussion, column numbers refer to the
chart on SRI 74.) Starting from the X-read lo gate, D2G 10
(column 13) current flows: To terminal 56 on the top diode
board (column 12), through a diode in diode pack 25 on the
top diode board (column 11 ), to pin 161 on top diode
Advertisement
Table of Contents
