40-A2, 20-A2, and 10-A2 Internal Fuse Replacement
The model 40-A2, 20-A2, and 10-A2 Loudness
Monitors are protected by an internal fuse, which is soldered
in the power supply section of the main circuit board. On
rare occassions, this fuse can fail as a result of power
line spikes or transients, resulting in a totally dead meter.
If you experience this symptom, check the fuse for contintuity
(assuming normal line voltage is being supplied to the meter).
CAUTION: Be sure the meter is unplugged from the mains supply
before performing this check.
To gain access to the pico-fuse, the meter
case must be removed. Locate fuse F76 on the main circuit
board it looks similar to a small black resistor (highlighted
area in the illustrations below).
Check the fuse for continuity. If open, replace
with a 1.5/2.0A pico fuse. Power the meter up before reassembling
to ensure no further problem exists .