Elenco Electronics M-1150K, Сборка и инструкция по эксплуатации

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TROUBLESHOOTING CHART
This chart lists the condition and possible causes of several malfunctions. If a particular part is mentioned
as a possible cause, check that part to see if it was installed correctly. Also, check that part and the parts
connected to it for good solder connections.
PROBLEM POSSIBLE CAUSE
No DC voltage reading 1. Check for open fuse.
Refer to Figure 7 for a better understanding 2. Check resistors R2 through R9 for correct values and
of how the meter works. good solder connections.
3. Check that the PC board is seated properly and that
the three board clamps are engaged.
4. Check D3 and D4 for shorts.
5. Check R1 for an open connection.
6. Check the meter movement. Unsolder the red wire
from the meter movement to the PC board. Place a
51K
Ω
resistor between the red wire and the positive
side of a 1.5V battery. Connect the negative side of
the battery to the black wire from the meter move-
ment. The meter should read a little over half scale.
Wrong meter readings 1. Check resistors R24, R25 and R2 through R9 for cor-
rect values and good solder connections.
No AC voltage reading 1. Check for open fuse.
Refer to Figure 8 for a better understanding 2. Check diodes D1 through D4 for opens and shorts.
of how the meter works. 3. Check resistors R13 through R16 and capacitor C1
for correct values and good solder connections.
No DC current reading 1. Check for open fuse.
Refer to Figure 9 for a better understanding 2. Check resistors R10, R11, R12 and R26 for correct
of how the meter works. values and good solder connections.
Ohms 1. If meter cannot be zeroed:
Refer to Figure 10 for a better understanding A. Check for open fuse.
of how the meter works. B. Check for weak or improperly installed batteries.
C. Check that the battery snap and battery con-
tacts are installed correctly.
D. Check resistors R19 through R25 for correct
value and good solder connections.
2. If meter does not read correctly:
A. Check R19 through R25 for correct value and
good solder connections.
No hFE reading 1. See Ohms above.
Refer to Figure 11 for a better understanding 2. Check that the test leads are in the correct socket
of how the meter works. for the type of transistor being tested.
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