Fault diagnosis of S9 dynamometer
bus routes: Metro Line 3 → Metro Line 5 → S5 Yuzhu Xinzhou route, the whole journey is about 15.4km
1. Take Metro Line 3 from TIYU West Road, pass by 1 station, and reach Zhujiang Xincheng Station
2. Take Metro Line 5, pass by 8 stations, and reach Yuzhu station
3. Walk about 950m to Yuzhu wharf station
4. Take S5 Yuzhu Xinzhou route, pass by 1 station, Arrive at Whampoa Military Academy dock station
5, walk about 180 meters to the memorial hall of Whampoa Military Academy
over
descendants of Huangpu Military Academy!
Address: No.170 Changzhou Junxiao Road, Huangpu District, Guangzhou. There are 21 bus stops near the general station of Huangpu Military Academy in Guangzhou, which are Huangpu District Government (89 meters), Wenchong market (298 meters), Sano intersection (322 meters), dashadong (361 meters), Huangpu sports center bus station (406 meters)
brief introction to Huangpu Military Academy:
Huangpu Military Academy, full name of the Military Academy of the Republic of China. It is one of the most famous military schools in modern China. It has trained many famous commanders in the Anti Japanese War and the civil war between the Kuomintang and the Communist Party. The first to six period of the first Kuomintang communist cooperation period was originally located in Changzhou Island, Whampoa District, Guangzhou City, China (sixth phase has Wuhan branch). The military academy was founded by the Chinese mainland in 1924, aiming to train officers for the national revolution, and is the main force for the unification of China by the national government in the Northern Expedition war. The Military Commission was founded in 1924. Huangpu Military Academy was transformed into the Central Army Academy in 1927, and then into the Army Academy in 1946
root belongs to the modification of operating system software, which is not included in the warranty scope according to the regulations. In order to improve customer satisfaction, Samsung provides free firmware upgrade service for root customers. If the root has affected the mobile phone hardware and needs to replace the motherboard, it needs to charge the motherboard fee
if your machine needs to be restored to the original system version after root, please send it to Samsung Service Center for after-sales engineers to help check and handle it. It is impossible to cancel the root permission by restoring the device to its factory settings.
the standby power indicator is on, which indicates that the control system crystal is working and the power supply of the control system is normal. The indicator light of the second power on can flash, indicating that the standby working process of the control system is normal. At this time, if the control system can not be started, there must be a fault in the circuit outside the control system (Note: this kind of fault determination has been introced in the previous issues of this journal, not too much analysis here)
the indicator light flashes ring the second startup, indicating that the control system has received user instructions. And through the decoder in CPU, it is converted into the instruction to control the indicator light (this circuit works under the basic conditions of CPU), and the PWM pulse width control signal is controlled from the output pin of CPU indicator light, so that the indicator light works in the on-off state, and then it shows flashing
the main reason why the TV has a long second boot time is that there are many unit circuits controlled by the bus. During the boot time, the control system has to communicate with all controlled circuits and reset the circuit state
if the indicator light doesn't flash at all when the second power on is executed (the purpose of flashing is that the screen of the control system is usually black when detecting the controlled circuit. In order to make the user feel that the TV is working, it is designed to flicker), and the machine can't be started, so it can be confirmed that the failure of the whole machine is in the control system. Generally, the working state of tuner, sound processing and digital processing circuit of HDTV (or flat panel TV) is controlled by bus, and these bus signals are usually sent out after the second power on
in other words, the bus voltage is close to the pull-up voltage of the power supply ring standby, and the bus voltage will drop after the second power on because the bus is loaded
if the oscilloscope is used for measurement, it can be found that the bus pin will have changed data waveform after the second power on. The bus voltage of ic-sca and ic-sda of pins (31) and (32) in Figure 1 is 5V in standby (because they are connected to 5V power supply through resistance r240 and r241). After the second power on, the bus voltage drops and jumps around 22V. As shown in the figure below, the bus voltage from the chd-6 movement control system to the main board tuner is 5V in standby mode, and changes between 4.7V and 4.9v after the second boot
it can be seen that it is unnecessary to check the bus load of the control system to the controlled circuit for the fault machine that can not be started up again. It's the same with ordinary CRT TV
if the TV proced by tda8843 is used, it is unnecessary to check the tda8843 and the sound effect processing circuit if the whole machine does not perform the second power on action
the inspection should be carried out around the control system circuit. As shown in the circuit structure in the figure below, if the bus pin voltage of the tuner is 5V and no data waveform can be seen, the control system (flash block, address latch, etc.) should be checked instead of checking the main board tuner, sound effect block, tb1307 on the digital board and the load svp-cx12 crossed by the parallel bus
generally speaking, when the power pin is in high level, it is in standby mode, and when the power pin is in low level, it is in power on mode. Turn on the power, press the local key to start the machine, and the power pin level is always high, indicating that the control system is not working. If the control system is working, it will continuously detect the level of the remote control input pin and the local key control pin according to the time sequence, so as to execute the command
it can be seen that when the power on button is pressed, the level of the on / standby pin does not change, indicating that the control system is not working (excluding the power pin circuit). In order to solve the problem that the TV can not be turned on, we must first find out where the components of the TV are wrong
according to the methods listed above, we can basically find out the reason why the TV can't be turned on. I hope what Xiaobian provides can help you.
