HP (Hewlett-Packard) HP 85660B ユーザーズマニュアル

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the two front panel INSTR CHECK 
 turn on when the LINE switch is set to ON
and within a few seconds turn off (indicating no digital problems), but symptoms (such as
improper CRT display or improper response to particular commands) indicate that the
problem is in the digital area, a “LONG POP” can be performed. LONG POP is very
similar to the normal POP except an additional processor check is performed, all of the
RAM locations in Digital Storage 
 Memory) are checked, and the memory (RAM) on
the Al5 Controller is verified.
Since these more extensive checks require altering information that has been stored in
RAM, LONG POP requires an internal jumper on the Al5 Controller. To perform a LONG
POP:
Set the LINE Switch to STANDBY.
Place a jumper between ST or STS to T3
On Al5 Controller (HP part number 85660-60209) jumper 
 (STS) to 
 On Al5 Controller (HP part number 85660-60245) jumper 
 (ST) to
 (T3).
(Refer to Al5 Controller Component Location Diagrams for location of test points).
Set the LINE switch to ON.
When LINE switch is then set to ON, the two red INSTR CHECK 
 are forced on and
the main processor steps through the Self Test routine, expanding the normal POP by the
additional tests mentioned. The expected results for a LONG POP are exactly the same as
for the normal POP of INSTR PRESET as described above under “Front Panel INSTR
CHECK I and II 
Because LONG POP is a “destructive test” (it alters any information that has been stored
in RAM), it should be performed only as a last resort effort in troubleshooting what
appears to be a memory or processor-related problem.
 
 
 
The Al5 Controller Self Test is run on power-up and after pushing the 
(
INSTRUMENT PRESET
]
key. Fourteen 
 
 through 
on the Al5 Controller give an indication of
the Self Test results. All 14 
 are forced on whenever the instrument is turned on or the
(
INSTRUMENT PRESET
key is pushed. The main processor 
 then performs a check of
itself, a check of the Peripheral Interface and Timer chip, a checksum verification of all the
ROMs on the Al5 Controller, a read/write check of the 
 on the Al5 Controller, and an
Instrument Bus check that checks the I/O Bus, Address Bus, and Data Bus for stuck lines.
If 
 the checks pass, the 14 
 are turned off serially as each check is completed. If the
checks fail, one or more 
 remain on. Refer to Table 1, “A15 Controller Self Test Fail
Indicators,” at the end of this troubleshooting section.
Other failure modes to look for are:
a. If the 14 
 turn on but are all turned off at the same time (instead of sequentially), the
Peripheral Interface and Timer chip has most likely failed.
b. When an I/O failure is indicated (DS3, DS4, or a combination of these 
 remain on), it
may become necessary to use an oscilloscope to locate a stuck line.