HP Portable PLUS - Page 77

Portable PLUS Computer
Troubleshooting 8-11
Table 8-2. Diagnostic Test Results (Continued)
Test Result
Assembly·Level
Component·Level
Oscilloscope
Replacement
Replacement
Routines
Failure Codes (continued):
B-O: 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
J3 to con-
connector
J3 to con-
nector
J2 in receptacle
nector
J2 in receptacle
noted previously. Then
noted previously. Then
if no • A-O' error, re-
if no • A-o" error, re-
place
memory drawer
place memory drawer
PCA; if • A-o" error,
PCA;
if • A-O' error,
replace piggyback
replace piggyback
PCA. PCA.
For 1M-byte
memory
For 1M-byte memory
drawer, replace the
drawer, replace the
memory drawer PCA.
memory drawer PCA.
A-ROMyyL
.. .
For receptacle noted For receptacle noted Plug-in ROM read
A-ROMyyH ...
previously, check that previously, check that Find plug-in ROM
jumpers are in proper jumpers are in proper
locations~; swap locations
1
; swap
known good ROM at known good ROM at
socket marked yyL or
socket marked yyL or
yyH~; replace ROM
yyHl;
check ROM
PCA or ROM IC as PCA using scope rou-
indicated.
tine, or replace
ROM
IC, as indicated.
Messages:
Broken loop
Try
new cable; check
Try
new cable; check
HP-IL
connections; check
connections; inspect
I/O plate (or swap
internal connections to
and retry); replace the I/O plate assembly (or
motherboard PCA.
swap assembly and re-
try); check continuity
of HP-IL interface cir-
cuit (see schematic);
replace
A2U15 (HP-IL
controller).
Loop error,
data not Remove peripherals
Remove peripherals
HP -IL
received as sent
and run the HP-IL
and run the HP-IL
test; try new cable;
test; try
new cable;
check connections;
check connections;
bad HP-IL peripheral;
bad HP-IL peripheral;
check
I/O plate (or
check
I/O plate (or
swap and retry); re-
swap and retry); check
place
the motherboard
HP-IL components us-
PCA . ing scope routine;
replace
A2U15 (HP-IL
controller).
J