HP (Hewlett-Packard) 3490A Car Stereo System User Manual


 
START
BEMOVE
ASCII
INGUAFD
A$EMALIES
Ag AND
436. INSTALL
REMOAE
JUMP,
EF
BOAFD
44
ISUPPLIED
WtTB OPTION
OSI IN CONNECIOR
A1J7 IN
PLACE
OF
AS.
SET 34SA
RANGE
ANO FUNC-
TION
TO TEST
i TO
VEFIFY
COFFECT
OPERATION
OF
MAIN
LOGIC.
FEMOVE
A4 ANO REPLACE
Ag AND
436.
MESURE
+
12 V.
+
5
V, ild
-2
V
OUTGUAND
VOLTAGES.
+I2V
AND
.2V
AEST POINTS ARE
ON
A32
AND
+5V
TEST
POINT
IS
ON
A33. VOLT.
AGES
MUST
BE
MESURED TO OUT.
GUAAD
GFOUND TEST
POINT
ON
433
OR A3O.
ALLOW
+/,1ü
TOLLEflANCE.
ARE VOLTAGES
CORRE
TFOUBLESHOOT OUTGUART
AGE
SUPLIES.
+12V
.d
+
PLIES ARE LOCAT€D ON OU
MOTHEF
EOAFO
A3I.
.2
V SI
trVELOPED
FROM SYSTEM
MULTIVIBAATOF ON
A32,
MENURE
+
12V
ANO
.2V
SUPPLiES
q
IilGUARO ROM
SEMBLY A34.
THESE AR€ ON TEST POINTS
ON A34.
MENURE TO INGUAFO
GROUNO
AT
EST
POINT
ON AS,
CHECK OPEAATION OF
ISOLATING
PHOTO.TFANSISTOAS
U1 THAOUGH
UII WIIH A
LOGIC
PROAE
OR
AY
CONNECTING A KNOWN GOOD UNIT
IN
PARALLEL WITH THE
SUSPECTED
PHOTO.TRANSISTOB IN THE
g9OA.
A60 CHECK
DFIVE TRANSISTOFS
AM4 THROUGH
@ AND A35OI
THBOUGH
04. *
Note l.
TROUBLESHOOT
SUMLIES
GUARD FOM A$EMBLY AA.
FEPUCE DEFECTIVE COMPONENT.
THIS CHECK
A$UMES THI
ONE
GPIBPRINTED
CIFCUT
ALY
IS
DEFECTIVE.
USINC
ELIES
IN GPIB REPAIR
OAS8m. SUBSTITUTE
A$
ONE
AT A TIME IN THE FO
OROEB:
A32, AS. A36, A34,
LATION NS€MELIES A3O,
TOGETHER. AFTER
SUS'
EACH ASSEMBLY, PERFO
OPEFATING CH€CK GIVEN
GNAPH 5.7 OA '9 IO DETE
PROBLEM lS CLEARED,
Se
No
ffi
6E
CAFE IN HANOLItrG ISOLATION
NEMBLIES, PHOTO,TRANSISTOAS
U
1
DROUGH
!II AAE VERY S€NSITIVE
TO MECHAtrICAL
STRE$.
ilotEs:
1. THE ISOLATING
PHOTO-TRANSISTOBS
U1_II MAY BE
CHECKED
BY CONNECTINC A NEW PABT
IN PAFAL.
L€L
(ALL
FOUR CONNECTIONS)
WITH THE SUS-
PECTEO PAAT.
THE NORMAL VOLTAGE
OROP ACFO$
THE DIOOE
POATION
OF
THE PHOTO.TßANSISTOF
UNIT SHOULD
BE APPAOXIMATELY
I-75
V WHEN THE
UNIT IS
BIASED ON, ASL4_9 AND A35L1
5
ARE
FERRIT€
8EAN.
2, EACH TIME AN
SSEMALY OR PAFT ISSUBSTITUTEO
OR A REPAIF IS
MAOE, THE OPEBATTON
OF
THE
GPIS
CIACUITS
SHOULO 8E CHECKED USING THE PEAFOF-
MANCE CHECK IN PARAGRAPH
545, THE
COMPLETE
CHECK MAY
BE BUN, OA ONLY THAT PORTION
WHICH THE INSTRUMENT FAILEO PREVIOUSLY.
3490-D
-
3381