Fluke 8062A Instruction Manual page 86

8062A
Instruction Manual
Test and Symptom
Voltage Test - DC (cont)
High impedance dc readings
0.00, normal dc
readings correct
DC readings incorrect for
all ranges
DC readings correct for
200 mV, 2V incorrect
for 20V, 200V, 1000V
Voltage Test - AC
DC reading correct,
ac readings incorrect
Resistance Test
All ranges incorrect
All ranges incorrect
CR1 supplying proper current,
but reading off
4-24
Table 4-6. Troubleshooting Guide (cont)
Possible Cause/Suggestions
R1
Leakage from pcb, U3-6/7,
contamination
Input divider or input divider switches,
R2
Switches S3D, S3B
Check power supply connections
J13 Vss
J7 Com
J12 Vdd
Ohms source voltage inadequate -
using a voltmeter in the 2V or 20V
range, measure ohms source voltage
between TP11 and common. Refer to
Table 4-7 for correct values.
Q3, Q4, RT1, R2, R1, Z5
CR1 not supplying enough current
(particularly if 200
Select diode test, connect an external
1 k resistor across the inputs and
measure the voltage drop across the
resistor - should be approximately 1V
( 10%).
Check values of the reference
resistors for the range not working.
Check voltage drops across the
known and unknown resistors and
make sure the ratio works properly.
range noisy).