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


 
YTFTOTIS
AilD VERIFY NA.
ALFUNCTION.
\24U3 OR tjl|,
OEPENDII{G
>r srcral ts r{@RREcT.
IAVEFORMS
AT A28U6
PIilS
FTH SHOULO
BE
SIMILAR
MONITOR VOLTAGE
AT A2ATN
PIN
15
U'HIL€
CI{ANGING S/H STIITCH
FROil
OFF TO TRACK/HOLD.
A28U:l
PtN r3
GFOUT{D€D.
mot{t-
TOR VOLTAGE AT A2ATß
PIiI 16 WHILE
S/H SIYITCH
FROT OFF TO
OO€S VOLTAGE CHATGE WHEX
S{UITCH
FOSITIOT
IS CHAiIGED?
iTOI{ITOR
VOLTAGCS AT
PINS
II AND
I3 OF A28UTO WHILE REPEAT|TG IHE
TUTO PREVIOTJS
TESTS.
A28U2 IS PROBABLY DEFECTIVE.
DO€s VOLTAGE CHANG€ WHEf{
SIVITCH
POSITION
CHANGES?
a28t
8
ls
PnoEaaLY
o€FEcTtvE.
;AVEFORMS
AT A28UI4
F I7. SHOULD
BE SIiIILAR
o€s€RvEo AT
P|NS
3 AltO
Ä
Figure 7-15. Sample/Hold Logic
Troubleshooting
Tree.
REPLACE A28UIO
OR
UI6
AS INDI.
CAT€D BY IN@RRECT YYAV€FORI'
AI
A'BIJ6.
3490-
0-
3456
73317-34