HP 437B - ANALOG BOARD TROUBLESHOOTING (continued)

HP 437B
Service Sheet BD1
8-34
SERVICE
1 ms/DIV
Figure 8-4, A4TP3, 220 Hz Multivibrator Waveform
7. Set the oscilloscope as follows:
Vertical Sensitivity 0.0.00... .. cece eee e eee eens 50 mV/div
S WEED? Hadi Siistos seen Goals a Men dando h aaa aed ati 1 ms/div
THIGGEriNg wc. ccnse en ie caer eae cree ii de seed sb aaa ees External
Coupling: «ic cevcng cies dee cites dade aet th eee se AC
Connect
the
oscilloscope’s
external
trigger
input
to
A4TP3
(220
Hz).
8.
Connect
the
oscilloscope
to
A4U7
pin
3.
Verify
the
signal
shown
in
Figure 8-5. The signal level should be 0.12 Vp-p +0.01V.
ape eee
eRe
> MN LTLIEN LUN
aL_LILIT ET Tn
SCOICCECECITTH oy
ET TT TTT TT i
SE IV TELA YT
TTY AY
SeRRERRREE
es ee ea oye!
- 1 ms/DIV
Figure
8-5.
A4U7
pin
3
Range
Attenuator
1
Waveform
9.
Change
the
oscilloscope’s
vertical
sensitivity
setting
to
1V/div.
10.
Connect
the
oscilloscope
to
A4TP17.
Verify
the
signal
shown
in
Figure
8-6.
The
signal
level
should
be
between
2.00
and
11.00
Vp-p.
®