When inspecting a household set-top box, what items need to be checked, what common defects will appear?

Views: 80     Author: Site Editor     Publish Time: 2022-11-22      Origin: Site

Digital TV, network TV should be the development and transformation trend of today's TV, only in this way can more meet the requirements of consumers, if the TV itself does not have similar functions, it needs to be equipped with a set-top box, in the household set-top box inspection, will need to test what projects, what will appear in the common defects, let Xiaobian to tell you!

1. Prepare for the inspection

1) Determine the signal sources required by the STB test (such as various video, audio signals, WIFI signals, etc.)

2) Determine the required test disk and external equipment (such as headphones, USB flash drives, etc.)

3) Determine the voltage and frequency used

4) Determine the socket used

5) Determine whether the equipment is calibrated and whether the validity period is valid

6) Determine the number of sets of test equipment that can be supplied

7) Determine the test environment and equipment for Running test

8) Please provide the specification of STB.

2. Function check

1) Test voltage should be rated voltage and frequency

2) Security test

3) Shock test

4) Check the default software and hardware versions, default country, default language, and default time

5) Connect each signal source, test each output port, and observe whether the played image and audio are normal.

6) Test each key on STB: When changing different signal sources, camera test should be done to see whether there is any abnormality in image and audio

7) Test each button of the remote control

8)A TV, D TV(including Radio) check the total number of stations and check whether there are any leakage stations.

9) There is no abnormal situation during Channel conversion and AV/TV/ port conversion

10) Check the Smart Card jack and decryption function when using DTV

11) Test the image quality through Nokia Monitor Test and call the three primary colors, black and white screen to check the highlights/dark spots.

12) Test the connection lines and other accessories in the color box

3. Specific tests

1) Safety test standards can be referred to

IEC: International standard UL: American Standard (201106 edition)

2) Confirm whether the connecting cables are connected according to the requirements, and then plug in the power supply.

3) Note: All input and output interfaces on the TV need to be checked

4) After starting up, first do A TV, D TV(including Radio) search station check

5) Check with the factory about the number of analog, digital and broadcast signals that can be received under normal conditions before searching the station. Check whether there is any leakage during the test

6) When searching stations, it is necessary to search two kinds of signals of analog station and digital station respectively. The search time may take 10 to 30 minutes. You can focus on searching stations in advance before the test

7) When checking, search a good machine, not search a machine to partition

8) Install batteries in the remote control and use it to check the function of the TV.

9) Test each button of the remote control

10) Check the function of each key of the remote control, and each key should be responsive.

11) Whether it has backlight function (the picture shows the remote control with blue light function)

12) Check first:

(1) Default country

(2) Default language

(3) Software version

(4) Hardware version

13) Change the input signal sources in order to observe whether the images and audio played by the programs of each signal source are normal

During conversion, there should be no bad phenomena such as crash, flower screen, color loss or abnormal image

When changing different signal sources, we should do the camera test to see whether the image and audio are abnormal

14) Check the content

(1) 4:3, 16:9 picture

(2) TV and radio programs on ATV and DTV

(3) Programs of various resolutions

(4) To see whether there is a trailing, residual image

(5) Pay attention to the selection of station, turn signal source time is abnormal (analog and analog mutual turn

(6) During conversion, there should be no bad phenomena such as crash, flower screen, color loss or abnormal image

15) Check the content

(1) Select and watch digital encrypted TV programs (programs with a lock symbol) to determine whether the function of CI card is normal

(2) Check PIP picture-in-picture /CCD hidden caption test /Teltext teletext function

16) R/L channel, stereo, Limei, 5.1 channel stereo (R/L sound is not installed, speaker is not phase connection, R/L balance).

17) Set the sound to silent state through the remote control, and stay for 2 seconds, listen to whether there is redundant noise, high frequency sound and other sound output

18) Network TV: It is necessary to check whether the wired and wireless can be connected properly

In the sound test, each machine has to turn up the volume to see if there is any noise and distortion

19) Attention should be paid to the accompanying sound check:

(1) The volume should be moderate

(2) there is no delay, intermittent, noise, distortion, bee sound, bottom noise, mechanical vibration and low-frequency or high-frequency noise from components

(3) The phase is normal

(4) Switch machine, turntable, no obvious impact sound

(5) The accompanying sound should not interfere with the image

(6) It is required that when tapping the chassis and switching between high and low voltage, the accompanying sound is normal, and there should be no intermittent, distortion and other phenomena

20) Run the Nokia Monitor Test on the PC to check the specified picture quality. (To ensure the consistency of the test, the "standard" image mode should be used)

(1) Content of Nokia Monitor Test

(2) Mainly look at:

a. The five circles have deformation and raw edges

B.okia logo look for crosstalk

c. In the color scale, there are 40 small blocks of red and blue, each of which should be clearly separated. In the green scale, there are 40 large blocks, each of which has two small blocks, and these 40 large blocks should be clearly separated.

d. In grey scale, between 3% and 100% of the total 11 squares should be clearly separated.

e. overscan and overscan.

(3) Click the "Color" bar next to www in the main interface to carry out each monochrome test.

(4) Observe each monochrome picture

(5) Examination of the left and right vocal tract

21) Specific tests

(1) If the teeth of the lion's head are clearly visible, the clarity is OK

(2) Clarity check area, the number of clarity lines can be read (350, 400, 450 lines -- the displayed reading x10)

(3) Over the sweep inspection area, check the mark line of the sweep line (generally to 7).

(4) Corner clarity inspection area (the four small circles in the corner are the four corner clarity inspection areas, and the CRT corner clarity is worse than the central one)

22) 3D TV test:

(1) The picture should not flicker when watching

(2) Watch from multiple angles up and down to see a good 3D effect

(3) With good anti-crosstalk ability, watching will not see the phenomenon of double shadow

(4) Whether there is too dark phenomenon in the picture

23) After confirming the completion of the above tests, shut down the machine with the remote control (the power supply of the host is not cut off) and listen to whether there is abnormal noise output.

24) After the inspection, the TV should be reset to the factory setting. (This step can be carried out by the cooperation of the workers.)

4. Professional test (3 sets)

1) Pre-test warm-up: The test will start only after the performance is stable for 1 hour.

2) Infrared remote control front test

Long-distance test: 8 meters in front of the sensor head

Close test: 3 cm in front of the sensor head

3) Infrared remote control Angle test:

4) When the tester is 4.5 meters away from the TV, test whether the remote control and the TV receiving lens can work normally if the horizontal Angle is about 30°

5) Test whether the TV can work normally when the distance between the tester and the TV is 3 meters and the vertical Angle is 15° up and down

6) It can be divided into induction head test and remote control head test

(1) Sensor head test: The remote control is tested in four directions, and the remote control points to the origin of axis coordinates)

(2) Launch head test: The remote control is tested in front of the Y-axis direction, the position of the remote control remains unchanged, and the acceptance ability of the four directions of rotation is tested

7) Power test during broadcast

(1) Different test signals have different power

(2) ON MODE (AVERAGE) TESTING USING DYNAMIC BROADCAST-CONTENT VIDEO SIGNAL. Remember to indicate the signal you use in the report.

(3) The test time is 10 minutes, and its average value is taken

8) Power test when broadcasting TV programs

(1) The test time is 10 minutes, and its average value is taken

(2) Signal sources must comply with the requirements of IEC 62087:200x video content_DVD_50 through IEC 62087:200x video content_ HD_ DVD_60 The signal is tested.

9) standby power consumption test (should be less than 1 watt)

10) Specifications, color boxes and spec have mentioned relevant index tests.

Note: If the indicators mentioned in the specification, color box and SPEC cannot be confirmed or tested on site, Remark or information shall be made in the report.

Metrics that have not been tested cannot be written as confirmed or tested.

5. Confirmatory test (quantity: one)

1) Check the packing method (see whether the attachment will be out of place after transportation)

2) Check the content of the manual (every word, every sentence)

3) Color box,SPEC or BOM content check

4) Confirmation of plugs and power cords in relevant countries

5) ATV, DTV, Radio frequency range test (probe, tail, and information below indicate that only the small and large frequencies of these two points in each frequency band are measured in practice)

6) AFC function confirmation

7) HDCP protocol screen test

8) V-CHIP classification is determined

9) Sleep automatic switch setting and confirmation

10) Reset test (whether the changed language, volume, menu and other Settings can be restored to factory Settings)

11) EPG functional test

12) CA card test

13) Confirmation of the national television format used

14) Check the corresponding functions of the remote control

15) Use the necessary Approval mark of the country and the product to confirm

16) HDMI CEC function test

17) In WiFi, test whether the connection can be correctly connected under different encryption modes

18) Drop Test (1 corner, 3 sides, 6 sides) -- Before dropping, you need to check with the factory to see if this test is allowed. Special drop equipment should be used to test

19) After the drop test, attention should be paid to the internal inspection: the heavy components on the power board are prone to plate cracks around

20) Running test:

(1) Timer/clock check to set the current accurate time

(2) The voltage is set to the rated voltage, and the audio and video are played continuously for 4 hours

(3) PRV video test can be conducted at the same time

21) Internal check (number of samples: one)

Main IC, Tuner/transformer marking, Plug Main IC, tuner/transformer marking, plug

(1) Carefully disassemble the sample shell to ensure that the original position/state of the internal structure, components and internal wires of the product will not be affected.

(2) Check the internal wires and electrical connections. When the power cord enters the product, twist/pull/toggle the wires or connecting terminals with light force with your fingers if necessary to check the connection status.

(3) the wire should not be damaged, clipped, scald and other phenomena

(4) The wire should be properly protected to ensure that it does not come into contact with burrs, edges, heating/moving parts that may damage its insulation performance. The metal holes through which the insulated wires pass shall have smooth sufficiently rounded surfaces or be fitted with bushings

(5) The wire shall be connected, supported, clamped or fixed in an appropriate manner to prevent the stress on the wire and the connection or the loosening of the connection

(6) Check the color of the internal wires of the power cord, and it should meet the requirements

(7) Check the grounding (if any) connection and symbol

(8) Move the moving part and check whether it will touch other parts

(9) The bare wire shall be rigidly fixed

(10) Check the internal structure of the product and its process structure against the sample (if any). The structure of the product should be consistent with the sample. The plastic parts should not be damaged, melted, deformed, etc. The metal parts should not be rusted, damaged, etc

(11) Check screws and connections

(12) When removing the screw, it should be checked whether the screw can be fully fixed. It should not be twisted tightly or loosened

(13) Check the screw post after removal, there should be no burst, white phenomenon

(14) Screws or nuts for electrical connection or ground connection shall be fixed reliably and prevented from loosening

Common defects of home set-top boxes

1) The setting is incorrect 2) The image is abnormal 3) the display is abnormal 4) the interface has no function 5) The indicator is incorrect

6) Key problems 7) abnormal sound 8) Long search time