HP 3478A Technical Manual page 86

3478A 3478A
make sure the CPU's clock (at pin 2 and 3 of USO1) is at make sure the CPU's clock (at pin 2 and 3 of USO1) is at
approximately 5.856MHz. approximately 5.856 MHz. Try replacing cry
if the signal is still missing, try U5O1. if the signal is still missing, try U5O1.
Figure 7-D-1. 1. U501 ALE Figure 7-D-
c. c. Make sure th Make sure the RESET line e RESET line at pin 4
the line is low, try replacing USSO (see Schematic 4). the line is low, try replacing USSO
7-D-9. Turn-On 7-D-9. Turn-On Failure Failure
7-D-10. 7-D-10. The Turn-On Failure normally The Turn-On Failure normally shows up if all of
the following symptoms are noted. the following sy mptoms are noted. If only one sy
is noted, it is noted, it is not a tur is not a turn-on failure. n-on failure. The symptoms for a
turn-on failure are as follows: turn-on failure are as follows:
a. a. The The displa display y is is dead
can also be caused by a defective display, assume it is can also be caused by a defective display, assume it is
turn- on failure before troubleshooting the display. turn- on failure before troubleshooting the display.
b. b. The The keyb keyboard oard is in is inopera
If only the keyboard is inoperative, go to paragraph 7-D- If only the keyboard is inoperative, go to paragraph 7-D-
15 for troubleshooting. 15 for troubleshooting.
c. c. HP-I HP-IB B is is inope inoperativ rative. e. It It may
check for an HP-IB failure if the two previous symptoms check for an HP-IB failure if the two previous symptoms
were are noted were are noted. . If only an If only an HP-IB failure is note
paragraph 7-D-17 for troubleshooting. paragraph 7-D-17 for troubleshooting.
7-D- 11. 7-D- 11. If the pre If the previous symptoms vious symptoms were noted,
Flowchart Flowchart A A for for troubleshooting. troubleshooting. In In the
various address lines and data lines are checked, using various address lines and data lines are checked, using
Signature Analysis, to determine the faulty component. Signature Analysis, to determine the faulty component.
The faulty component(s) can be the Main Controller The faulty component(s) can be the Main Controller
(USOI1), Control ROM (U502), CMOS RAM (U512), or (USOI1), Control ROM (U502), CMOS RAM (U512), or
the HP-IB Chip (U503). the HP-IB Chip (U503).
7-D-12. Before t 7-D-12. Before troubleshooting roubleshooting for a
check the following: check the following:
a. a. Ma Make su ke sure t re the D he Data
good contact. If the pins good contact. If the pins are bent, the
Data Lines may be good, but the 3478A may be in- Data Lines may be good, but the 3478A may be in-
operative. operative.
b. b. Ma Make su ke sure ju re jumpe mpers JM
are in the "N" (Normal) position. are in the "N" (Normal) position. The 3478A will not
on at all or properly, if they are in on at all or properly, if they are in a different position.
Try replacing crystal Y501 and stal Y501 and
U501 ALE Signal Signal
at pin 4 of US01 is of US01 is high.
(see Schematic 4).
shows up if all of
If only one symptom
The symptoms for a
dead or or inope inoperati rative. ve. Since Since this
operative tive (does (does not not respo
may not not be be necess necessary
HP-IB failure is noted, go to
were noted, go to
the Flowchart, Flowchart, the
for a Turn-On Failure, Turn-On Failure,
ata Bus Bus Bre Break E5 ak E527 is 27 is maki
are bent, the signatures on the signatures on the
rs JMS01 S01, JM , JM502 502, and J , and JM50
The 3478A will not turn
a different position.
7-D-13. 7-D-13. Inoperative
7-D-14. 7-D-14. An inoperative
display is in display is inoperative.
display itself or part of the Chassis Common Circuitry. display itself or part of the Chassis Common Circuitry.
Before doing Before doing any tr
2.2V, and 3.3V power supplies to the display are good. 2.2V, and 3.3V power supplies to the display are good.
The supplies can be checked at R503 pins 9, 3, and 15 The supplies can be checked at R503 pins 9, 3, and 15
for the 3.3V, 2.2V, and 1.IV power supplies, respective- for the 3.3V, 2.2V, and 1.IV power supplies, respective-
ly. ly. If any supply If any supply is wrong, replace R503 and if still wrong,
replace the replace the display.
Flowchart B B for Flowchart
control lines to the display are checked, using Signature control lines to the display are checked, using Signature
Analysis routines, to determine if the display or another Analysis routines, to determine if the display or another
circuit is at fault. circuit is at fault.
high. If If
mptom
7-D-15. 7-D-15. Inoperative
7-D-16. An inoperative 7-D-16.
3478a operations cannot be selected from the keyboard. 3478a operations cannot be selected from the keyboard.
this
This can be caused by the keyboard itself or by the Main This can be caused by the keyboard itself or by the Main
Controller. The following proced Controller.
the Main controller (using Signature Analysis) that the Main controller (using Signature Analysis) that
receive the infor receive
respond). nd).
resultant signatures it is determined if the keyboard or resultant signatures it is determined if the keyboard or
the Main Co the Main Controller is defe
a. a. Tu
ary to to
b. b. Mov
d, go to
position. position.
c. c. Con
go to
follows: follows:
the
S S t t a a r r t t : :
S S t t o o p p : :
C C l l o o c c k k : :
H H o o l l d d : :
Self-Test: Out Self-Test: Out
G G n n d d : :
d. d.
making ng
signatures. signatures.
U5O1 pin 27: P6H5 U5O1 pin 27: P6H5
U501 pin 28: PF57 U501 pin 28: PF57
U5O1 pin 29: 08C6 U5O1 pin 29: 08C6
U5OI1 pin 30: 41PA U5OI1 pin 30: 41PA
M503 3
U501 pin 31: 35PU U501 pin 31: 35PU
turn
U501 pin 32: 62U5 U501 pin 32: 62U5
U501 pin 33: 27H3 U501 pin 33: 27H3
U501 pin 34: 6U19 U501 pin 34: 6U19
7-D-2 7-D-2
Inoperative Display Display
An inoperative display is w display is when all or pa
operative. The failure can be cause The failure can be caused by the
any troubleshooting, make oubleshooting, make sure the 1
is wrong, replace R503 and if still wrong,
display. If the If the supplies are
for troubleshooting. troubleshooting. In In the
Make sure grounded tools and wrist straps are Make sure grounded tools and wrist straps are
used, when replacing or checking the display. used, when replacing or checking the display.
Inoperative Keyboard Keyboard
An inoperative keyboard keyboard is when a
The following procedure checks the
the information from mation from the key
ntroller is defective. ctive. Do the fo
Turn rn th the 3 e 347 478A 8A of off. f.
Move ju e jumper mpers JM s JM502 502 and
Connec nect an t and set t d set the Si he Signa
T T P P 7 7 . . ( ( ) )
T T P P 8 8 ( ( ) )
T T P P 3 3 ( ( ) )
O O u u t t
C C h h a a s s s s i i s s G G r r o o u u n n d d
Turn Turn the the 3478A 3478A on on and
TM 11-6625-3071-14 TM 11-6625-3071-14
hen all or part of the rt of the
d by the
sure the 1. . IV,
supplies are good, go good, go to to
the Flowchart, Flowchart, the
is when all or part ll or part of of
ure checks the ports of ports of
the keyboard. board. From the From the
Do the following: llowing:
and JM5 JM503 t 03 to th o the "D e "D" "
gnatur ture Ana e Analy lyze zer as r as
and check t check the he following following
IV,
the