HP Portable PLUS - Page 76

8·10 Troubleshooting
Portable PLUS Computer
Table 8·2. Diagnostic Test Results (Continued)
Test
Result
Assembly·Level
Component·Level
Oscilloscope
Replacement
Replacement
Routines
Failure Codes (continued):
4rcc
Swap the keyboard
Swap the keyboard
(r is row number)
module, then retry. If
module, then retry. If
(cc is column number)
fixed, replace
fixed, replace
keyswitch (or key·
keyswitch (or key-
board module) after
board module) after
checking continuity; if
checking continuity; if
not fixed, replace the
not fixed, replace
motherboard PCA.
A2U16 (keyboard
multicontroller, or SIP
resistors A2R12,
A2R13, and A2RI4).
0: yy ... Memory PCA. ot
If only one or two
Internal RAM write
1: yy
...
RAM ICs indicated
Internal RAM read
2: yy
...
(see table 8-3), replace
3: yy .. .
individual ICs. (Note
that one IC corre-
sponds to several
codes.) Replace mem-
ory PCA.°t
If more than two
RAMs indicated, latch
or transceiver sus-
pected. Trace using
scope routine.
ot
A-O: yy .. . Memory drawer PCA Memory drawer PCA
Find plug-in RAM
in receptacle noted
in receptacle noted
previously. previously.
A-I: yy ... For standard memory For standard memory
Find plug-in RAM
drawer, move piggy-
drawer, move piggy-
back RAM PCA from
back RAM PCA from
connector J2 to con-
connector J2 to con-
nector J3 in receptacle
nector J3 in receptacle
noted previo usly. Then
noted previously. Then
if no 'B-O' error, re-
if no 'B-O' error, re-
place memory drawer
place memory drawer
PCA; if 'B-O' error, re-
PCA; if ' B-O' error, re-
place piggyback PCA.
place piggyback PCA.
For 1M-byte memory
For 1M-byte memory
drawer, replace the
drawer, replace the
memory drawer PCA.
memory drawer PCA.