Hitachi EUB-5500 ultrasound non-image
Failure phenomenon
The Hitachi EUB-5500 ultrasound equipment is turned on normally, but there is only noise and no image in the fan sweep area.
Troubleshooting
Hitachi EUB-5500 Ultrasound uses Windows XP as the system software, and it directly enters the ultrasound application after booting. If the power on is normal, it means that you can enter the operating system; there is noise and no image in the fan sweep area, but the surrounding characters are displayed normally, which means that the ultrasound application is not problematic. Just in case, use the randomly configured system CD and restart it by CD-ROM. The fault is still found, so the software fault is eliminated.
When the fault occurred, a phased array probe (FPA 2.5 MHz) was used. At the same time, the ultrasound was also equipped with another linear array probe (FLA 10 MHz). Switch the probe to a linear array probe. The noise in the fan scan area changed, but it still No image, adjust the gain, no image is seen, considering that the possibility of two probes being broken at the same time is very small, so it is judged that the probe is normal.
At the same time, it was found that when the probe was switched, no buzzing sound was heard when the probe crystal started to vibrate, indicating that the ultrasound probe was not activated and no ultrasound was generated. The parts that affect the generation and emission of ultrasound are: probes, channel boards, transmitter boards, front-end control boards and high-voltage power supplies, which need to be eliminated and analyzed one by one.
Exchange the positions of the above two probes, restart, and switch back and forth, find that the fault remains, eliminate the possibility of damage to the probe and channel board; re-plug and unplug the DBF, EPI and other functional boards, no improvement after restarting, eliminate the function The board may be loose; use an oscilloscope to check the transmit pulse trigger signal on the transmitter board, it is normal, and there is no red light on the transmitter board indicator, so it is impossible to determine whether the transmitter board is damaged; check the high-voltage power supply according to the prompts on the power board, and find ± The 80 VDC output is abnormal. The power supply provides power to the transmitter board, causing the transmitter board to fail to generate ultrasonic pulses, so there is no image in the fan scan area.
Take out the power board carefully, open the metal casing, and check with a multimeter. It is found that the fuses of F1 and F2 (250 V) have burst, indicating that the circuit has overcurrent or short circuit. The two high-power tubes responsible for providing ±80 VDC have been short-circuited. Remove the burned high-power tube and check the surrounding circuits carefully. No obvious abnormality is seen. Then replace the power tube and fuse of the same model. The power-on measurement ±80 VDC has been restored. The output of other power sources is normal. Connect the load and restart. It is found that normal image signals can be seen in the fan-scanning area. After burning the machine for 3 hours, the department replied that everything is normal. The fault has been eliminated.
