HP 3478A Technical Manual page 138

e. e. If an If any sig y signat nature ures are i
fault. Replace fault. Replace U501. U501. If If all
keyboard can be checked by doing the following: keyboard can be checked by
1. 1. Leav Le ave th e the Si e Signa
as in step c. as in step c.
2. 2. By pre ress By p ssin ing a c
the signatur the signature on a e on a port of port of U501 should
example, the signature on U501 pin 27 (port P10) example, the signature on U501 pin 27 (port P10)
should change from "P6H5" to "U878", if the a button is should change from "P6H5" to "U878", if the a button is
pressed. From this change, pressed. From this change, it can be
button (i.e., part of the keyboard) is inoperative or good. button (i.e., part of the keyboard) is inoperative or good.
The following lists the pin numbers of U501, the button The following lists the pin numbers of U501, the button
to be pressed, and the to be pressed, and the change in signature.
7-D-17. 7-D- 17. HP-IB Fai HP-IB Failure lure
7-D-18. 7-D-18. Before troubleshooting Before troubleshooting for inoperative
make sure the 3478A is operating correctly from the make sure the 3478A is operating correctly from the
front panel. Repair the fr front panel. Repair the front panel operation
troubleshooting for an Hp-IB troubleshooting for an Hp-IB failure.
HP-IB failure, go to Flowchart HP-IB failur e, go to Flowchart C.
flowchart checks the HP-IB Chip to determine if data flowchart checks the HP-IB Chip to determine if data
can be written to or read by the chip. can be written to or read by the chip.
7-D- 7-D-19. 19. U.C. ROM F U.C. ROM Fails ails
7-D-20. If the "U.C. R 7-D-20. If the "U.C. ROM FAIL" message is displ
(during a Self-Test routine), the most likely cause is a (during a Self-Test routine), the most likely cause is a
failure in Control ROM failure in Control ROM (U502).
is defective and not the Main Controller, go to Flowchart is defective and not the Main Controller, go to Flowchart
A (see paragraph 7-D-11) for troubleshooting. A (see paragraph 7-D-11) for tr
7-D- 7-D-21. 21. U.C. RA U.C. RAM Fails M Fails
7-D-22. If the "U.C 7-D-22. If the "U.C. RAM FAI . RAM FAIL" message is displayed,
the failure is most likely in the Chassis Common CPUs the failure is most likely in the Chassis Common CPUs
RAM (RAM RAM (RAM in Main Controller in Main Controller U501).
RAM is defective, go to Flowchart A (see paragraph 7- RAM is defective, go to Flowchart A (see paragraph 7-
D-11) for troubleshooting. D-11) for troubleshooting.
s are inco ncorre rrect, U ct, U501 ma 501 may be at
all signatures signatures are are correct, correct, the
doing the following:
gnatu ture A re Ana naly lyzer zer con
g a cer erta tain f in fro ront p nt pane anel bu
U501 should change. change.
it can be determined if t determined if the
change in signature.
for inoperative HP-IB,
ont panel operation first, before first, before
failure. To troubleshoot To troubleshoot an
C. The procedure in the The procedure in the
OM FAIL" message is displayed
(U502). To make sure To make sure the ROM
oubleshooting.
L" message is displayed,
U501). To make sure the To make sure the
y be at
7-D-23. 7-D-23. Calibration
the
7-D-24. 7-D-24. If the "CAL RAM
(after a Self-Test routine), the most likely cause is a (after a Self-Test routine), the most likely cause is a
conne nect cted ed
Calibration RAM Calibration
RAM can be checked by sending data to the RAM and RAM can be checked by sending data to the RAM and
reading it back. reading it back.
l butt tton on, ,
For For
he
a. a. Tu
b. b. Mov
position. position.
c. c. Con
follows: follows:
HP-IB,
an
d. d. Tur
signatures. signatures.
ayed
U512 pin 9: H709 U512 pin 9: H709
the ROM
U512 pin 11: C577 U512 pin 11: C577
U512 pin 13: 4296 U512 pin 13: 4296
U512 pin 15: 8U25 U512 pin 15: 8U25
e. e. If an
Data Bus is Data Bus is defective.
paragraph 7-D-11) for troubleshooting. paragraph 7-D-11) for troubleshooting.
f. f.
be defective. be defective. The RAM can
with the test in the next step. with the test in the next step.
7-D-4 7-D-4
Calibration RAM RAM Failure Failure
If the "CAL RAM FAIL" message is di FAIL" message is displayed
RAM (CMOS (CMOS RAM, RAM, U512)
CAUTION CAUTION
Make sure grounded tools and wrist Make sure grounded tools and wrist
straps are used, when replacing or straps are used, when replacing or
checking the display. checking the display.
CAUTION CAUTION
The test in paragraph 7-D-24 cannot be The test in paragraph 7-D-24 cannot be
made without destroying the present made without destroying the present
data in the Calibrati data in t he Calibration RAM. on RAM. The 3478A
must be recalibrated, after doing the must be recalibrated, after doing the
test. test.
Turn rn th the 3 e 347 478A 8A of off. f.
Move ju e jumpe mpers J rs JM50 M502 and 2 and JM5
Connec nect and t and set t set the S he Sign ignatu
Turn the n the 347 3478A on 8A on and c and chec
If any sig y signat nature ures are wr s are wrong
defective. Go to Flow Go to Flowchart A (see
If the s If t he sign ignatu atures res are are goo good, t
The RAM can be checked by continuing be checked by continuing
TM 11-6625-3071-14 TM 11-6625-3071-14
splayed
U512) Failure. Failure. The The
The 3478A
JM503 t 03 to th o the "D e "D: :
ature A re Anal nalyze yzer as r as
heck the k the fol follow lowing ing
ong, some , somethi thing on th ng on the e
chart A (see
d, the R he RAM ( AM (U51 U512) m 2) may ay