1 fault phenomenon
Can start normally, in the selection of phased array probe (2.5MHz) and in areas of the image has no beginning
and wave, noise only, cannot of diagnostic ultrasound scanning. Figure 1 shows the image on the monitor.
Then switch to linear array probe (10MHz), had a began to wave in the areas in the image, but only the normal
of about 1 / 3, far field part no echo. Increase the gain, the noise will increase, can not carry out clinical diagnosis.
2 Analysis of maintenance
According to the fault phenomena analysis, ultrasonic emission part system fault suspected. The generation and
emission of the ultrasonic wave is mainly included: probe, channel board, launch plate, front control panel and high
voltage power supply. Therefore, it is necessary to check the system step by step to further reduce the fault range.
First, check whether the normal probe. Pull the probe into another socket, and then see if the switch is normal.
After inspection, the probe switch is normal, fault phenomenon is still. This shows that the probe, the channel
board this part of the normal operation. Then, then check the transmit pulse, the normal. When the detection of
high voltage power supply, the power output is not + / - 80V. This shows that there is a fault in the high voltage
power supply. High voltage power failure, will cause the launch board can not produce ultrasonic pulse output,
also can not have the initial wave image display.
3 troubleshooting
From the chassis will remove the high voltage power supply module, open the metal shell, using a multimeter were
detected, two fuse has burned off, indicating that the high voltage power supply internal short-circuit fault. After
measurement, it is found that there are two transistor short circuit breakdown. Replacement of the same
specifications of the transistor and the insurance tube, short-circuit fault exclusion. After the high voltage power
supply module is loaded into the machine, the power is switched on, and the system is restored to normal.
