Initial Test -- 2
Ok
Procedure
Place the ground lead of your voltmeter on the anode (opposite the banded end) of D1.
This is ground reference for all measurements.
Apply 13.8V power to JP5.
Measure the voltage on the 9V bus by connecting the other lead of the meter to the
cathode of D1. This should be 9 volts, ±0.25V. If not, fix the problem before
proceeding.
If you have an ammeter, measure the current draw on the 12 volt input. It should be
less than 25ma. If it is significantly more, there is likely a short circuit.
Remove power from the circuit.
Integrated Circuit Installation -- 2
Integrated circuits are polarity sensitive devices. The small notch in the body is on the end with pins 1 and 8.
Make sure the notch on the component matches the one on the silkscreen!
Do not mount the MAX477 ICs in sockets! Using sockets could lead to circuit instabilities.
Ok
Procedure
Install a MAX477AD8055 IC at IC2, IC2, IC3, IC4, IC5, IC6, IC7.
Solder and clip 42 leads.
Next
Initial Test -- 3
Ok
Procedure
If you have an ammeter, connect it in series with the 12 volt power lead and make this
test.
Apply 13.8V power to JP5.
Measure the current draw. It should be about 60ma. If it is over 150ma, there is likely a
short in the DC bus. If it is more than 70ma and less than 150ma, there is likely a
spurious oscillation. Check to make sure you've installed the 100 ohm resistors at the
inputs to IC2-IC7 with the body of the resistor closest to the IC.
Remove power from the circuit.
