HP Portable PLUS - Reference Information for a and B Versions; Troubleshooting a and B Versions; Replaceable Parts for a and B Versions

11-4 Product History
Portable PLUS Computer
11 .3 Reference Information for A and B Versions
This section presents reference information for troubleshooting and repairing A and B versions of the
Portable PLUS. (The version is indicated by the model number printed on the bottom label of the
unit-refer to table 1-1.)
11.3.1 Troubleshooting A and B Versions
Troubleshooting procedures for A and B versions are identical to those presented in chapter 8 with
one exception: ROM and RAM IC identifications differ from those for E and F versions. Table 11-2
lists actions you should take for the indicated diagnostic test results.
Table 11-2. Diagnostic Test Results for A and B Versions
Failure Code
Assembly-Level
Component-Level
Oscilloscope
Replacement
Replacement
Routines
116-118
Memory PCA.
If only one or two
Internal
ROM read
127-129
ROMs indicated, re-
place individual
A1U16-A1U18 or
A1U27-A1U29
(ROM).
If more than two
ROMs indicated, latch
or transceiver sus-
pected. Trace using
scope routine.
0: yy Memory PCA. If only one or two
Internal RAM write
RAMs indicated, re-
Internal RAM
read
place individual RAM
ICs:
0:00 .... A1U26
0:08 .... A1U22
0:01 .... A1U15
0:09 .... A1U11
0:02 .... A1U25
0:10 .... A1U21
0:03 .... A1U14
0:11 .... A1UlO
0:04 .... A1U24
0:12 .... A1U20
0:05 .... A1U13
0:13 .... A1U9
0:06 .... A1U23
0:14 .... A1U19
0:07 .... A1U12
0:15 .... A1U8
If more than two
RAMs indicated, latch
or transceiver sus-
pected. Trace using
scope routine.
11.3.2 Replaceable Parts for A and B Versions
Table 11-3 lists certain replaceable parts for A and B versions. Other parts are as listed in chapter 9
except as may be noted in section 11.2 above.