Sencore FE149 - Page 15

SYMPTOM PROBABLE CAUSE CORRECTIVE MEASURE
Cannot zero meter; Open resistor or circuit Place temporary jumper be-
meter reads past full to gate of ТКІ or TR2 tween terminals 6 and 10 on
Scale on DC volts or TRI is deféctive large PC board. If meter can
now be zeroed, open exists in
resistors R43 to R50 or wiring
on small PC board. Check
small PC board with ohmmeter.
If meter cannot be zeroed with
jumper RIT CRI2ZMC26 or
TRI are defective. Check
CR12 and C26 for short, or
R1 for open.
Replace TRI if necessary.
(Specify color when ordering)
Zero adjust requires Battery voltage dropping Operate from power line for
frequent adjustment several hours to charge
battery to normal voltage.
Rechargeable battery Charging circuit not Check voltage at CR4. Re-
runs down functioning place defective CR4, R26,
(СИНОМ CRS, ТІ, Ss, Ore line
cord, if voltage is low
or missing.
CR3 leaky Replace CR3
Battery defective and Check battery and replace if
will not hold a charge it will not hold a charge
Cannot make measure- Poor connection to Check connections
ment on one current switch or resistor on this
range. range
Open resistor Replace open resistor
Inaccurate readings Resistor value changed Check resistor value or
one one current range range in question and replace
resistor if off value.
Inaccurate readings Resistor value changed Check resistor value on range
on one ohms range in question and replace
resistor if off value. In
RX1 ohms range, check and if
necessary, adjust Lo ohms
cal control
o- buttons stickor Foreign material or Remove unit from case and
efuse to push in particles around moving clean inoperative button and
arm of button lubricate with a good tuner
cleaner with silicone such as
"Blue Stuff" or "Super Wissh
with Silicone".
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