With the improvement of people's living standards, the requirements for quality of life are also increasing. Many families install home audio systems at home to achieve surround sound effects similar to those in cinemas, for watching movies or listening to music. How to conduct inspections on products like home audio and what testing items are needed? The editor has summarized the relevant content. If you find it useful, don't forget to collect it

1. Audio inspection process

1) Packaging inspection

2) Appearance inspection

3) Safety inspection (60065)

4) Functional inspection

5) Special inspection (aging, wiping, tension, internal inspection, etc.)

6) Parameter testing

2. High voltage test parameters

EN60065: 3000VAC/5mA/2S &Nbsp; UL60065:1200VAC/10mA/2S

3. Function testing

The difficulty of audio inspection is that the sound we hear cannot be seen (which is also a chaotic waveform on the oscilloscope), cannot be touched, and everyone's hearing varies From the user's perspective, individuals have their own preferences, some particularly dislike the buzzing sound of amplifiers, and others particularly dislike the buzzing sound of bass, all of which increase the difficulty of testing We must undergo long-term training, develop sharp hearing skills, and accumulate experience in order to identify various product defects

4. Tuner (radio) inspection

1) Band switch (button for electric tuning products) inspection

Common problems: no function, poor function,

Reason: poor incoming material, Poor assembly or foreign objects such as rosin seeping into the switch

2) Frequency coverage inspection

Inspection method: Adjust the platform to 560KHZ (low end) 1600KHZ (high end) 88MHZ (low end) 108MHZ (high end), and the test signal sent by the factory should be clearly heard.

Common problem: coverage deviation (phenomenon: signal cannot be heard at high and low ends)

Reason: deviation in the factory's three-point adjustment

3) Sensitivity (Shutdown Sensitivity) Inspection

Inspection Method: Manually adjust the frequency to 600KHz/1000KHz/1400kHz &Nbsp; 90MHz/98MHz/106MHz, the test signal sent by the factory should be clearly heard, with a loud and undistorted sound. Electrically tuned devices should stop at the above frequency

Common problems: disorderly shutdown, low sensitivity, sound distortion

Reason: deviation in the factory's three-point tuning, imbalance in the high amplifier circuit, etc.

4) Full frequency band sound quality inspection

Inspection method: From low to high frequency, use a cloth wrapped wooden hammer to strike the product, and the entire frequency band should have clear and distorted sound Common problems: howling, clapping, ringing, and noise

Reason: False soldering, false soldering, component too close, component shaking

5) Stereo (lighting sensitivity) inspection

Inspection method: Adjust the channel to the factory generated stereo frequency, and the difference between the stereo and the active channel should be clearly heard

Common problems: no stereo, separation check, light (indicator) does not light up

Original  Due to poor adjustment of the 38KHz subcarrier signal