e. Check for a 60 cps beat. See paragraph 4-5. nient develops trouble symptoms not covered by this
chart, repair analysis will be simplified if the Circuit
f. Make a final recheck of frequency calibration on Description given in this manual is used to obtain a
all six ranges. Make any adjustments found to be complete understanding of the instrument circuitry.
necessary. In case of persistent trouble. contact your -hp- Sales
Engineering Representative or the -hp- Factory Serv-
ice Department directly.
g. Check instrument response to line voltage change.
See paragraph 4-5.
All circuit references refer to Figures 4-9 and 4-10
h. Check output impedance and maximum output volt- unless otherwise noted. Signal. ac. or dc voltages
age. See paragraph 4-5. when mentioned here. are measured between the in-
dicated points and the chassis unless specified other-
4-7 TROUBLE SHOOTING wise.
Notes given in Table 4-2 are based on -hp- experience. Tubes with standard RETMA characteristics can be
The more common troubles. their symptoms, and used for tube replacements as explained in paragraph
remedy are given. 4-4. In a great number of cases, instrument trouble
can be traced to a defective tube. Avoid transposing
It is beyond the scope of this manual to include all tubes of the same type in their respective sockets as
possible or obscure and rare troubles. If an instru- this may disturb instrument adjustment.
TABLE 4-2. TROUBLE SHOOTING
SYMPTOM CAUSE AND/OR REMEDY
Dead on all ranges. Blown line fuse
Tube V13, V14, or V15 defective.
Rectifier V10 defective.
No. B+ voltage.
No B+ voltage or Low B+ voltage. Rectifier V10 defective.
Tubes V6 and/or V7 defective.
Tube V8 shorted.
Choke L7 open.
Resistor R37 open.
Defective filter capacitor.
R34 open.
High B+ voltage. Cannot be adjusted by Tubes V6 or V7 shorted.
R35 control.
Tubes V8 or V9 defective.
Resistor R36 open.
[nstrument blows line fuses. Shorted rectifier V10.
Shorted filter capacitor.
Choke L7 shorted to chassis.
Defective power transformer.
Shorted heater wiring.
Power supply will not regulate with varying Defective tube in regulated power supply.
line voltage.
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