Static Measurements; Resistance Test; Power Up Test - Elenco Electronics SUPERHET AM-550TK Assembly And Instruction Manual

You have completed wiring the Audio Amplifier. We shall proceed in testing this circuit. You will need a Volt-Ohm-
Milliammeter, preferably a digital type.

STATIC MEASUREMENTS

RESISTANCE TEST

Adjust the Volt-Ohm-Milliammeter (VOM) to the highest
resistance scale available. Connect the VOM to the
circuit as shown in Figure 3. Do not connect the battery.
The VOM should indicate a low resistance first and then
as C14 charges,
approximately 100kW.
Amps COM
GND
R15
Figure 3

POWER UP TEST

Set your VOM to read the highest possible current.
Connect the meter to the circuit as shown in Figure 4.
Make sure that the On/Off switch (SW1) is in the OFF
position.
While watching your VOM, flip switch SW1 to the ON
position. The VOM should indicate a very low current.
Figure 4
resistance should rise
If you get a lower reading,
W
V/W
reverse multimeter leads. If you get a reading lower
than 20kW, check the circuit for shorts or parts inserted
incorrectly. Check C14 to see if it's leaky or inserted
backwards. If you get a reading higher than 150kW,
to
check for open copper or bad solder connections on
resistors R13 and R14.
Adjust your meter for a more accurate reading if necessary.
If the current is greater than 25 milliamps, immediately turn
the power off. The current should be between 5 and 15
milliamps. If you circuit fails this test, check that all parts
have been installed correctly and check for shorts or poor
solder connections. Turn OFF SW1.
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DC Amps
Amps COM V/W