استكمل موضوع ال EEPROM والجزء الاساسي المتصل به او الذي يعمل معه MCU
Circuitry of TVs in the last ten years, has undergone significant changes. Auxiliary control device earlier in modern TVs become one of the main components - the processor control. Is charged with multiple functions - from the remote control, operational and service adjustments to video games and the teletext signal processing . Under the "freeze" of the processor should be understood that when the TV is in working mode it immediately or after a period of time does not respond to the remote control button and the local keyboard. Reasons may be several:
● too high or much too low voltage processor
● increased ripple voltage regulator;
● Avoid the impulse reset RESET;
● retire the clock;
● closed one or more buttons to the local keyboard;
● faulty control bus;
● faulty processor.
I hope readers will have its own work to find the causes of changes in the supply voltage, which allows the author to do the following reasons for this defect. Ripple voltage arise, as a rule, loss of capacity iz_za oxide capacitors PSU.
For example, the TV SHARP, assembled on the chassis 5BS 5BSA and, after four years of operation to change nearly all oxide capacitors BP, Horizontal and Vertical, especially S714, S716, S712 and S713 (see Figure 2). Ripple may increase with excessive increase in current consumption of one of the stages, powered by the same rectifier as the processor. At the entrance of the processor RESET normal stress should be approximately equal to the supply voltage (typically +5 V). Only when the TV is on this pin with external elements form a negative reset pulse. If you have a voltage regulator on the RESET pin voltage is too low or when the reset pulse is missing, check the reset circuit, and if it contains an oxide capacitor, the first thing to check is his. If the power of the processor in the normal scheme of relief items are intact, and the RESET pin CPU voltage is too low, it should be considered a defect in the CPU itself. Modern TVs have recently used special chips that form the reset pulse, so if there is no signal on the processor RESET condition and also check that chip. To synchronize the operation of all units of the processor, it contains a clock with an external crystal oscillator.
The characteristic defect is substandard soldering pins crystal. Another defect recoverable clock, leading to hang the processor, is the fault of the quartz resonator, which can be determined by the method of substitution. If extreme conclusions crystal connected to the body through the capacitors, these capacitors also need to check and replace them with a known good. Buttons local keyboard can be connected to different processors in different ways.
The three main strategies to incorporate in Fig. 1. The first one (Fig. 1, a) does not require further explanation. In the scheme of Fig. 1 b by pressing one of the keys of changing the DC voltage at the corresponding input of the processor, which is recognized by the processor and decoded in a team. This is the maximum voltage (about 5 V) when the button is not pressed, and the lowest (0) while pressing S1. One of the most common is the circuit of Fig. 1, in which the keyboard is a matrix that has multiple inputs and outputs. The inputs of the keyboard with the pulses of the processor, out-of-phase with each other (see Fig. 1c). Depending on which button is pressed, one of the outputs will be one of the input pulse, which is decoded by a processor in a particular team. The defects of this type of keyboard often lead to hang the processor. Should check whether the button and close the leaks between the terminal buttons and clip, which serves to stiffen the mounting buttons (especially if the cage is grounded). More convenient to perform the operation, carefully cutting the printed conductors between the buttons and the corresponding pins. If no button is pressed, the DC voltages at all entrances matrix keyboard are the same and may differ from napryaezheny for outputs, which must also be equal. Button to check if the voltage on one input (output) matrix keyboard is different. This defect is characterized by the company for TV SANYO, assembled on the chassis Series A2, although found in other devices. The processor communicates with the slaves on a digital bus. The most common two-wire digital bus I2C (development firm PHILIPS) and three-wire digital bus IM (ITT Inter Metal). Certain portion of faults that lead to a "crash" of the processor - is fault management bus. In Fig. Figure 2 shows the relationship of the processor with a tuner, and a memory chip video processor via I2C. Both bidirectional bus line: SCL - line clock (clock) and SDA - data line. Of the ten resistors in the circuit are required only two - R7 and R8, called pull-up. The necessity of these resistors is due to the fact that within the digital chips are pin tires installed cascades open collector (drain) and R7, R8 - this is the external load resistors. Remaining resistors circuit - current limiting and is protective. Part or all of the limiting resistors TV manufacturer can not install. These schematics are used for other digital bus. In Fig. 3 is a similar scheme for IM_shiny where D-line data, C - line clock (sync), and I-line identification. From these lines only D - two-way, and C and I - unidirectional. For more details about Digital tire  and . To increase the rate of exchange of the television, use two, three, and the information in some of the digital control tires. In normal operation, the DC voltage on the lines of most of the tires is from 4 to 4.9 V. If the voltage on at least one of the lines of the digital bus is too low, this indicates a violation of data exchange. The first thing to check, whether the podsazhena line processor, or one of its managed chips. In the presence of limiting resistor is easy to do. To do this, in turn, measure the voltage at the terminals of the resistor in relation to the case. If the findings of which will be kakogo_libo different voltage, the chip, where it is connected, it should be considered a defect. If limiting resistors are not available, you need to turn off the conclusions of the devices that are connected to podsazhennoy line, as long as the mode to recover it - it says that the last trip from the bus chip is faulty. At the same time, if possible, do not use solder - better to turn off the existing process connections (for example, taking charge teletext, tuner, etc.). Voltage drop on one of the lines of the digital bus can also occur iz_za break pull-up resistor connected to the bus.
When the TV processor can check (scan) as the keyboard and the configuration of the system (using the color system and TV_standartov, availability of teletext, setting menus and teletext language, etc.). In modern devices, these settings are made in the service mode, and in the earlier models, they were asked by the hardware. To do this, the processor had a special scan port (output), between which and several other findings processor connected diodes. Number and connection points of these diodes specify certain characteristics set. When a leak is detected in one or more of these diodes can happen "freeze" the processor. Processor may hang due to a fault or a memory chip iz_za that defective self. The site Telemaster  in "Secrets of repairing televisions. Part 2 "by the secret number 125, hiding behind the pseudonym" Alexander S Petersburg ", has offered an unrivaled way to restore hangs with heating processors TMP47C434N R 214 TV FUNAI, which in a few years a radio CIS spread over hundreds of different processors with a similar defect. The essence of this method is that a faulty processor is heated 30 ... 50 with the flame lighters and give it to cool naturally. So can not recover more than 80% of freezes earlier processors.
The latest processor, which was restored to the author of these lines, using the heater - a processor 47C834_R181, set the TV CORFUG MS_5200. The reader must have noticed that the proposed methods in this paper are focused on troubleshooting minimum instrumentation. This is useful when working in the home of the owner. When repairing a TV in a stationary shop to check the clock, reset pulse, pulse scanning keyboard pulses and bus control is desirable to use an oscilloscope.
Restoring television microcontroller controlled heating method
CEA repair experts in their practice are constantly faced with a problem when the TV, VCR or DVD-player ¬ fully or in part out of order y ¬ ravlyayuschy processor (microcontroller ¬ ler). In such cases, one alternative - replacing this chip. But, given that the gain necessary microcontroller is not always possible, and the cost can be quite large, many such chips is reduced rather unconventional way - namely, by their controlled heating. This will be discussed in the promotional material.
Many repairmen are well known problems associated with defects television series TMR47Shhh microcontrollers used in televisions FUNAI. The defect can be quite different from full to partial loss of functionality of the microcontroller (no OSD, inability TV on from standby mode to work, the inability to control the TV from the front of the TV, and with the remote control, etc.). Since these devices fail often enough, was offered an interesting way to restore their health. The essence of the method is that a faulty processor for some time heated to 13 ° ... 15O ° C.
Such temperature "training" can be made in a laboratory oven, and in a domestic environment (in the kitchen oven or on the stove).
Since not everyone has the opportunity to use a thermostat on the last version, we discuss in more detail. Faulty processor is placed, for example, in a pan, then fill it with any oil (the best food). Oil to a conductor of heat for uniform heating of the body of the chip. Then put the pan on the burner stove or in the oven. Body temperature control chip produced by a laboratory thermometer. Using a standard means of temperature control panel (oven) nedopus ¬ Timo because their statements have a significant error, which, in the final analysis, ¬ nom, can cause overheating and eventual circuit failure. The duration of this "hot" processor - up to five minutes (most of it is enough, and one minute). The greatest effect is achieved if the heating of micro ¬ controller is available in several stages: first, the chip is heated for one minute, then cooled, and the same operation is repeated two more times. Then, if the microcontroller does not restore its performance, like the cycle is repeated twice more. It is usually sufficient to perform the first three cycles (reduced to 40% of the processors).
Now for the statistics. Most easily restored television series processors and TMR47Shhh S68hhh - up to 90% for the rest of the positive effect is achieved in 50% of cases.
I want to add that there were few attempts (successful) recovery in this way not only television processors and controllers, video recorders and DVD-players - all of these devices, and unfortunately, there is insufficient statistics.
As for the reasons why the CPU temperature after training recovers by itself, the most likely explanation for this phenomenon is that when heated restored electrical connections (for whatever reasons previously broken) between the semiconductor crystal ¬ thallus and the pathways that connect it to the external leads of the chip. In fact, this problem seriously, few engaged - at least in the popular literature, information on such issues not only had some pretty lively discussions on a few "maintenance" forums. To the same problem finally "stalled", we invite readers to share their information and statistics on it, as well as offer other innovative solutions for the repair of equipment ..................... . № 4 "Repair & Service" in April 2006