Whirlwind MCT7 - Multi Connector Cable Tester - Manual (Page 5)

time as the Ground LED, then all those pins have a short to ground. This test only
functions for the female XLR and 5 pin DIN (MIDI) connectors. See Fig. 1g.
Note : In case of the mini (3.5mm) and 1/4” (6.3mm) jack plugs, there are two
versions, mono and stereo. When testing mono plugs and the pin selector knob is in
position 1 or 3 the LEDs 1 and 3 will light. See Fig. 1h. Notice that in this case the Pin
Selector Switch is in positions 1 and 3 respectively.
Testing and Replacing the Battery
If you place the Pin Selector Switch to position number five, the LED marked
“B” will light, this means the battery is good. The intensity with which this LED lights is
proportional to the battery’s charge. See Fig.2.