Testing Of The Dynamic Microphone At The Headset With Cable (Hmd 46-3-X Only); 5.2.4 Operational Testing Of The Headset Cables; 5.2.5 Audio Testing Of The Headset Without Cable - Sennheiser HME 46-3 Service Manual

5.2.3 Testing of the dynamic microphone at the headset with cable (HMD 46-3-x only)

Reference: See fig. 1 "Operational test of the dynamic microphone" page 13
A. Operational testing
1. Connect the microphone connector of the headset with the negative and positve line into the
audio amplifier input, see "Cable connector´s pin alignment", page 14 or see "Wiring diagrams", page 15
et sqq.
2. Connect the headphone connector of the headset with the negative and positve line into the audio ampli-
fier output, see "Cable connector´s pin alignment", page 14 or see "Wiring diagrams", page 15 et sqq.
3. Connect the oscilloscope into a free amplifier output, see "Operational test of the dynamic microphone",
page 13
4. Speak into the microphone of the headset:
- The speaker´s voice will be audible without any distortion in both capsules of the headset.
- The amplified audio signal of the speaker´s voice will be displayed via oscilloscope.
B. Testing of the capsule via resistor measurement
1. Set the multimeter into resistor measurement mode.
2. Connect the multimeter at the relevant pins of the cable connector, see "Cable connector´s pin alignment",
page 14 or see "Wiring diagrams", page 15 et sqq. Result: The multimeter displays 200 ohms ± 10 % for
correct connection of the cable and the capsule. There is no failure or breaking in the cables.

5.2.4 Operational testing of the headset cables

References
•
see "Cable connector´s pin alignment", page 14.
•
see "Wiring diagrams", page 15 et sqq.
A. Conductivity test:
Set the multimeter into the conductivity mode and check each cable from the connector to the system
connector for conductivity.
Operational test of the PTT-button:
B.
The contactivity is available when the PTT-button is pressed.
For the following testing procedures disassembling of the headset is necessary.

5.2.5 Audio testing of the headset without cable

A. Testing audio via PCB at the PCB socket P1, see "Printed circuit boards", page 19.
1. Supply 1 kHz signal at the PCB socket P1.
2. In the headphones, the 1 kHz tone must be audible.
B. Testing of the acoustic transducer.
1. Set the sine wave generator to 100 mVeff ± 5 mV with a signal of 1 kHz to the PCB. Set a signal to TP8 (+)
and TP9 (-), see "Printed circuit boards", page 19.
2. In the headphones, the 1 kHz tone must be audible.
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HME 46-3, HMD 46-3
02/2008