[Abstract] Objective : To solve the problem of high maintenance cost of large medical equipment through the discussion of chip-level maintenance of large medical equipment. Method: The essence of research on the chip-level maintenance of medical equipment is to study and track the problematic chip through the fault phenomenon. Describe in detail the specific requirements of chip-level maintenance and the analysis of various methods of chip-level maintenance to illustrate the feasibility of chip-level maintenance. Results: The operation and maintenance costs of medical equipment were significantly reduced. The use of chip-level fine repairs saved 60% to 90% of maintenance costs compared to direct replacement of module boards. Compared with the manufacturer's direct replacement module, the board-level maintenance is only 10% to 40% of its price. In the past few years, it has saved millions of dollars for the hospital, and the benefits are obvious. Conclusion: It is completely feasible to perform chip-level maintenance on the faulty board of medical equipment. Chip-level maintenance is a feasible and necessary way for the hospital equipment department to carry out maintenance work in the future. 1 chip-level maintenance specific requirements 1.1 Improve the professional quality of staff As a maintenance engineer, you must master the basic knowledge of analog and digital circuits and the basic knowledge of electrical engineering, understand the circuit principle, application and basic power common sense, and analyze the working process of typical circuits. Modern large-scale medical equipment is inseparable from computer components, which requires engineers and technicians to be familiar with the composition and structure of computer systems, to understand the relationship between hardware and software components in computer systems, to have certain computer operation skills and related knowledge; Use the language to read a variety of manuals and learn basic search skills. Chip-level maintenance requires maintenance personnel to have good hands-on operation ability, flexible fingers, clean movements, no mud and water, can be planned in a planned manner and step-by-step operation according to the predetermined design. Medical equipment such as CT and DSA have both sophisticated data processing modules and high-voltage parts. Therefore, when testing such medical equipment, it is necessary to have a good safety awareness and develop good maintenance habits. Not only to ensure your own personal safety, but also to ensure the safety of maintenance equipment, maintenance tools, to avoid personal injury and equipment damage caused by indifferent safety awareness. As a maintenance personnel, you must develop good habits. For example, when using electricity, ensure that the socket and the electrical equipment are firmly plugged in, and that the parts are plugged or unplugged without power. When using the soldering iron, be careful to keep away from inflammable and explosive materials. After use, power off and place the soldering iron in an absolutely safe place. 1.2 Maintenance equipment requirements Commonly used maintenance tools are essential: multimeters, hot air soldering stations, heterosexual screwdrivers, crowbars, magnifiers, tweezers. The multimeter is mainly used for detecting current, voltage and resistance, judging whether the components on the circuit board are good or bad and whether the interface is normal; the oscilloscope is mainly to measure the input and output signals of the chip to understand the working state. For higher-level chip-level repairs, the use of multimeters, general oscilloscopes, and off-line testing of devices is no longer adequate, so newer types of repair equipment are needed to accommodate higher requirements. (such as IC online tester, short circuit tracker, writer, memory oscilloscope, logic analyzer, precision welder, etc.). 1.3 Maintenance environment requirements Chip-level maintenance has higher environmental requirements than "dough" maintenance. First of all, we must ensure that the maintenance environment is safe and clean. It is best to use a 1:1 isolation transformer for safe power use. Secondly, since the internal insulating layer of the large-scale integrated circuit is thin, the wiring pitch is small, and the breakdown voltage is low, the antistatic capability is very weak. Therefore, the maintenance environment requires high anti-static measures. General anti-static equipment includes: anti-static workbench, anti-static component box, human anti-static gloves, anti-static work cap, anti-static overalls, anti-static wristband. 2 Method of performing chip level maintenance The essence of researching chip-level maintenance of medical devices is to study the tracking of problematic chips through fault phenomena. The difficulty of an engineer in troubleshooting depends on two aspects: first, the complexity of the fault itself, and second, the familiarity of the machine mechanism and principle. The difference between the two levels determines the way in which fault tracking is locked in different situations and must be treated differently. 2.1 Simple fault repair method For boards with simple structure or familiarity with the principle, a step-by-step method can generally be used. For chip-level maintenance, first use the diagnostic software, block diagram, signal flow diagram, and fault status indicator provided by the medical device to determine and narrow the fault range. Solve the problem by identifying the faulty board and then analyzing the fault areas on the board by various methods. After confirming the faulty board, analyze the role of each area of ​​the board and go through the details of the board to find the faulty component through the fault phenomenon. Generally, each board has several obvious (such as cpu), and there are always some peripheral circuits on the periphery of each core chip. Board failures should first be suspected of short-circuiting, open circuit, etc. of discrete components around the chip. Some online states of flip-flops, registers, and selector ICs are often closely related to the state of other IC devices in the circuit. The peripheral-connected chips and circuits should be detected first. After confirming that there are no problems with the peripheral circuits, Then check the core chip. If the fault of the power module is usually manifested as subsystem power supply burnout or the supply current is greatly exceeded. Generally, the DC resistance of the power supply terminal of the circuit board is more than one hundred to several hundred ohms. If the value is obviously low, the chip or device with short-circuit damage on the board indicates that if there are only a few ohms or close to zero, there are chips on the board. Or device breakdown. Short-circuit faults can sometimes be visually detected to break down blackened faulty devices. If the fuse is not burned, the power is turned on for 5 to 10 minutes, and the temperature of the faulty chip is mostly overheated, which is significantly higher than the normal chip. Maintenance example Laparoscope Sony monitor has no raster and no image after power on, and the standby indicator lights. For CRT monitors, maintenance personnel are generally familiar with it, and such faults can be checked step by step based on the knowledge acquired. From the principle of the monitor, the fault should focus on checking the power protection and control circuit. During maintenance, open the cover and use the multimeter to measure the T650 secondary circuit ±20 V, +135 V, +13.5 V, +6.5 V DC voltage at the start-up moment. The DC voltage drops rapidly from the normal value, indicating that the microprocessor can enter according to the user's instructions. In the programming operation, the switching power supply can also enter the wide pulse oscillation state in response to the operation control of the microprocessor. The fault is caused by the protection circuit starting control or the power ON/OFF circuit operating abnormally after the power supply enters the work, and immediately returns to the standby state. Disconnect R055 in the composite protection circuit and the fault will not change. The control output voltage regulator IC2603 (2) pin, IC2601 (2) pin, IC460l (2) pin output voltage is always 0 V, measured its control terminal (4) pin, found that the voltage is only 1.1 V, the normal should be 4.9 V . Retest IC003 (11) foot voltage is 5.0 V, after inspection, it is found that the internal resistance of the resistor R059 is broken, and the machine is faulty after replacing R059. Losing Weight Plant Extract,Senna Leaf Extract,Bulk Senna Leaf Extract,Senna Leaf Extract Powder Youth Biotech CO,. Ltd. , https://www.youtherb.com