- Ask the user
After getting a mobile phone to be repaired, don't rush to do it, but first ask about the fault phenomenon, the time of occurrence, whether there is an instruction manual, the usual working condition of the machine, whether it has been collided or broken, whether someone has repaired it, etc., and pay attention to the appearance of the mobile phone, whether there are obvious cracks and defects. If the clamshell is gone, the antenna is broken, and the keyboard is bald, you can roughly judge the fault of the machine, and ask whether the machine is a second-hand phone, whether it has been repaired elsewhere, and how many years of use it is. These may seem like small problems, but they are very important for the next step of maintenance. For example, if the machine has been overhauled, the components in the machine may have been replaced, and the place where the machine has been welded should be paid attention to and restored during the overhaul, so that the maintenance can avoid detours. If the machine works in a humid environment or has been flooded, you can't power it on at will, so as not to expand the failure. Therefore, for an excellent maintenance technician, in the process of inquiring about the fault, you can roughly judge the scope of the fault and the components that may fail, so as to lay the foundation for efficient and fast troubleshooting.
- Master the correct operation method
Repair mobile phone will not use the mobile phone, just like repairing a car will not drive a car, some maintenance personnel are very vague about the operation of the mobile phone, change the ringtone, change the vibration, automatic timing, the last ten caller number display, call forwarding, check MEI code, phone number book function, the display and modification of the year, month and day in the machine are very unfamiliar, and even do not know the meaning of the status indicator of the mobile phone: the traffic light flashes alternately to indicate the call, the red light flashes out of the service area, and the green light flashes in the service area. Even the menus can't be adjusted correctly, and it's impossible to fix the phone.
- Master the correct disassembly and assembly skills
Because the shell of the mobile phone is generally made of thin-walled PC-ABS engineering plastics, its strength is limited, and the mechanical structure of the mobile phone shell is different, and there is a structure of screw fastening, inner buckle, and outer buckle, so for the installation and disassembly of the mobile phone, the repairer must be careful, see clearly in advance, and then disassemble on the basis of understanding the mechanical structure, otherwise it is very easy to damage the shell.
The disassembly and installation of mobile phones is a basic skill of mobile phone maintenance, and some mobile phones are easy to disassemble and install, such as Ericsson 788, T18 and other mobile phones. But there are also many mobile phones, especially some new mobile phones, if you can't master the trick of disassembly and assembly, it is very easy to disassemble.
- Observe the fault phenomenon
After opening the cover, the board should be visually inspected. Check whether the cable is loose and broken, whether the components are soldered and broken, whether the contact pieces are damaged and corroded, etc., and can be energized only after the inspection is correct, and the fault phenomenon can be recorded.
- Determine the scope of the fault
According to the fault phenomenon, various possible causes of the fault are judged, and a fault range is roughly delineated to narrow the fault. For example, the failure to turn on the machine, generally occurs in the power supply circuit or 13M generation circuit, welding and testing should focus on repairing these parts, and the radio frequency circuit and audio circuit that have nothing to do with the failure do not lightly "move the hands, feet".
- Test the key points
After judging the approximate fault range, the suspicious points should be repaired first, if the fault can not be eliminated, the voltage, waveform, frequency of the key points can be tested, combined with the working principle to further reduce the scope of the fault, which is very important, but also the difficulty of maintenance, requiring the maintainer to usually accumulate more information, accumulate more experience, record more normal data of some key points, and provide a basis for analysis and judgment.
- Troubleshooting
After finding out the cause of the fault, it can be replaced for different faulty components, when replacing components, it should be noted that the replaced components should be consistent with the models and specifications of the original components, if there is no same component, the information should be searched to find out the components that can be replaced, and the faulty components must not be replaced casually.
- Whole machine test
After troubleshooting, the functions of the machine should be tested to make it fully meet the requirements, for some soft faults, should be powered on for a long time to see if the fault will still appear, and so the fault is completely eliminated, and then handed over to the user, in order to maintain their own maintenance reputation.
- Keep a maintenance log
Keeping a maintenance log is like a doctor recording a medical record, and every time a machine is repaired, the following records must be made: what kind of machine it is, what the fault is, and how long the machine has been used; How to fix it, took those detours, etc. These maintenance logs, which seem to increase the workload, are actually a good way to learn and improve themselves, and also provide a basis for repairing similar mobile phones or similar faults in the future.
