Maintenance process: cell phone connected to the power table, press the power button, no current response, first measure the power button whether the voltage is disconnected, can be directly diverted to the power IC 32 feet directly to the power button short measurement of the power IC 18 # 20 # 22 # 25 # 27 # 48 # a voltage output, replace the power IC. 32.768 whether to start after the power supply output, measured with an oscilloscope. Frequency measurement 26M clock start, such as the first test whether there is power supply, power supply is to replace 26M. No power to change IF IC. Measured CPU T1 J4 B2 U1 is foot clock-26M-powered – Reset. If no, may be disconnected. Measured power IC24 pin reset signal output, replace the power supply IC. The educational department has approved the cell phone jammer system plan.
The above conditions are met, the normal detection font information, write data to detect the boot to maintain signal The absence of the CPU is bad. Samsung GSM cell phone several typical failure analysis and exclusion: we look at the normal boot need to go through those process: Press the power button → boot instructions to the power IC module → power control pins of the IC signal → the power IC → CPU; 13MHz master clock power → CPU reset and complete the initialization process → CPU issue the poweron signal to the power IC → Power IC stable output for each unit operating voltage → cell phone that opens, and then enter the network search stage of registration. According to the boot process, we can analyze the following relevant parts of the inspection and processing to be carried out. The president of the school is reporting the using situation ofcell phone jammersystem.
The more frequently the cell phone’s power button to use, this button is bad? Power IC module Weld or burn? Operating current of the IC, so the probability of failure is high. Power IC with or without boot signal to the CPU? A road load of the power IC with severe leakage or short circuit, causing the power-current, thus protecting the shutdown. The common point of failure is the PA or PA MOS switch burned. CPU pins Weld? This is a common point of failure. Normal CPU, three basic conditions are met: (a) 3V operating voltage; (b) 13MHz clock; (c) reset circuit. CPU whether the output the poweron signal to the power IC? The expert will provide the technical guide ofcell phone jammer.
Initialization software error? Re-write the software to give it a try. Note: check such failure, may be artificial separation of the defective unit, or man-made cross-connected (available for a short fine enameled wire) plus a voltage to the the poweron feet of the power IC, if the power supply IC for each able to output the normal voltage, the point of failure is generally the CPU control section or software, on the contrary point of failure in the power IC part or the load. Check failure, according to the direction of the signal processing from front to back inspection, may also be forward to check, you can also check from one place in the middle, the specific methods depending on the specific circumstances and cell phone models. The technical guide is necessary for use, repair and maintenance of cell phone jammer.