Two Cases of Hitachi EUB-5500 Ultrasound Machine Troubleshooting and Repair

1.1 Failure Phenomenon

The machine cannot start normally. After powering on, the progress bar reaches1/3and then crashes. After shutting down and restarting, the same failure phenomenon occurs.

1.2 Failure Analysis and Troubleshooting

HitachiEUB-5500Normal startup: After turning on the circuit breaker and pressing the power button, the control panel background indicator light lights up, the display shows the reading progress bar, and after the progress bar reading process is completed, it will display the information that the system is starting, and then "Now setting system data.Please wait." startup screen appears, and then after the ultrasound system starts, it enters the frozen state of the two-dimensional mode.

The machine crashes when the progress bar reaches1/3It can be inferred that the machine system orPCpart has malfunctioned, resulting in a crash. After reinstalling the system and testing the machine, the progress bar is still displayed1/3and the machine crashes, ruling out the possibility of a machine system failure. HitachiEUB-5500machinePCThe main board,MAPboard andPB2board inside the part may cause the machine to crash during startup. After re-plugging theMAPboard andPB2board and testing the power-on, the same crash failure still occurs, ruling out the possibility of poor contact between the plates. Replacing theMAPboard,PB2board and main board one by one for testing, after replacing the main board, the machine starts normally and enters the ultrasound two-dimensional work interface. The machine runs normally after multiple restarts, and the machine fault is eliminated.

2.1 Failure Phenomenon

Close the machine circuit breaker switch and press the power button. The machine does not respond, the control panel indicator light does not light up, and the display does not display and the indicator light does not light up.

2.2 Failure Analysis and Troubleshooting

HitachiEUB-5500The ultrasound machine normally starts through2processes. In the first process, after closing the machine circuit breaker switch, the machine is connected to the mains220Vand stepped down by the internal transformer of the power supply to110Vand input to the internal circuit board of the power supply, the machine enters the standby state. The second process is that after pressing the machine power button, the machine receives the startup signal, the power supply starts to work, and the machine starts normally.

Judging from the failure phenomenon, there is a fault in the machine's power supply. Further measurement110Vvoltage is normal, indicating that the power supply is connected to the mains, and there is a fault in the standby circuit. After replacing the power supply and testing the power-on, the machine is powered on and started, the control panel and display indicator lights are on, but the display is black and there is no display. The machine starts2minutes and then automatically powers off. When restarting the machine, there is no response. After the machine's power supply is replaced and the power-on test is performed, the control panel keyboard is usable before the power failure, but the ultrasound function key indicator lights are not lit. This indicates that there is a fault in the replaced power supply or a short circuit fault inside the machine may cause the power supply's internal protection action. Because the machine is not connected to the workstation, the display is black and it is impossible to determine which process the machine has started. After inquiring with the hospital department staff, it was found that before the machine failed to start, the display was normal and the machine could start and run normally. It is judged that the possibility of a fault in the replaced power supply is greater. Another power supply with a normal test result was retrieved and replaced, and the machine started and ran normally, and the machine fault was eliminated.

This HitachiEUB-5500machine repair encountered setbacks due to a fault in the power supply used for testing and replacement. After disassembly, it was found that a field-effect transistor on the circuit board inside the power supply was poorly soldered and fell off, while during the repair of the original faulty power supply of the machine, multiple components were found to be damaged, resulting in a standby circuit fault. After the machine was repaired, in communication with the hospitalBultrasound room staff, it was found that although this HitachiEUB-5500machine was shut down normally after use every day, the staff did not turn off the circuit breaker switch after the system was shut down, resulting in the machine always being in standby state, and the standby circuit in the power supply was always in a powered-on working state, which seriously shortened its service life.