Hitachi EUB-5500 color ultrasound machine fault repair

1.1 Malfunction Phenomenon
After powering on, the system cannot enter the normal system interface. The desktop displays “Now Setting System data Please wait… (The system is setting up, please wait…), and the prompt persists after a long wait.

1.2 Malfunction Analysis and Troubleshooting
The Hitachi EUB-5500 ultrasound application software relies on the Windows XP system. When the system runs to “Now Setting System data”, the system has started and completed setup, and the ultrasound application software is starting and calling relevant setting parameters.
This type of malfunction is often caused by unexpected power failure of the ultrasound, abnormal shutdown, incorrect operation, etc., resulting in damage to the configuration file. The application software cannot call the configuration file normally, so it keeps prompting that the system is setting up. Generally, deleting the later configuration file and restoring the factory settings can restore the normal startup of the system. Then, re-set and save the parameters.
Normally, after each adjustment of the setting parameters, a backup operation of the relevant files is required. In daily work, even if no malfunction occurs, it is necessary to regularly back up the setting files, so that if the system encounters software malfunctions, the relevant setting files can be restored in time, shortening the malfunction repair time.

2.1 Malfunction Phenomenon
After powering on, the operating system cannot be entered, the screen is black, and the prompt is No operating system.

2.2 Malfunction Analysis and Troubleshooting
This malfunction is generally caused by two situations: ① Damage to the underlying Windows operating system files, the system cannot normally boot the boot file, resulting in the inability to enter the Windows operating system. This can be solved by repairing the system or reinstalling the system; ② Hard disk damage prevents the system from reading the boot file normally. Even if the system is reinstalled, this situation will still report the same malfunction, and the hard disk needs to be replaced and the system reinstalled.

3.1 Malfunction Phenomenon
After the circuit breaker is closed, press the power button, the machine does not respond, and all indicator lights on the operation panel and display are not lit, and the fan does not rotate.

3.2 Malfunction Analysis and Troubleshooting

The power supply box fuses are measured to be normal, and the input voltage is measured to be 220V normal. The 220V voltage is stepped down to 110V by the transformer inside the power supply box and input to the power supply board. The 10V voltage is measured to be normal. The two circuit boards in the power supply box are removed and carefully inspected. It is found that the PNP transistor with Model number D858 is cracked, and the measurement also finds that some other components around this transistor are damaged.
The Hitachi EUB-5500 ultrasound normally powers on in two steps.
The first step is to close the circuit breaker switch, and the 110V voltage is conducted into the circuit board. At this time, the startup circuit in the power supply box has started to work and is in standby mode, waiting for the startup signal.
The second step is to press the start button, the switch is turned on, and a low-level start signal is sent to notify the power supply box to start working.
The circuit where D858 is located is the standby circuit. The standby circuit malfunction causes the power supply box to fail to receive the normal start signal, preventing the power supply box from starting normally. After replacing the D1858 transistor and surrounding components, the machine recovers.
This malfunction is relatively common in the Hitachi EUB-5500 ultrasound, and there are two reasons:
① It is related to the operating personnel's usage habits. After the machine is used every day, it is not shut down according to the normal shutdown procedure, and the circuit breaker switch is not turned off after the system is shut down, so that the standby circuit in the power supply box is always in the energized standby state, seriously affecting the life of this part of the circuit;
② The power supply box of the machine is not dusted in time, the filter screen is blocked, and the power supply box cannot dissipate heat normally, causing the circuit board to burn out due to overheating.

4.1 Malfunction Phenomenon
After powering on, there is no image in the image area, and the characters around the image area are displayed normally.

4.2 Malfunction Analysis and Troubleshooting
Switching to other probes, the system can identify the probe type, and the size of the image area will also change according to different probes, but there is still no image in the image area. Using the random system CD-ROM to boot from the CD-ROM, it can enter the normal operation interface in about 15 minutes. After the CD-ROM boot is completed, there is still no image in the image area, and the malfunction remains, basically ruling out non-software malfunctions. Open the rear cover of the ultrasound machine and the PC part, and re-plug the DBF (digital beamformer), AWP, EP (extended pulse imaging), MAP (Media Accelerated Processor) and other functional circuit boards. After restarting, the malfunction phenomenon does not change. Observing the indicator lights on each functional board, no red lights are found lit.
However, at this time, when the probe is placed close to the ear and listened carefully, there is a buzzing vibration sound inside the probe during thawing, indicating that the crystal inside the probe has vibrated, and the transmitting circuit part is normal. At this time, the malfunction is locked in the receiving or processing and display part. The receiving and processing parts mainly involve the DBF board, E board, and MAP board. The EP board and MAP board both belong to the PC part. The MAP board also includes two boards, M1 and M2, which are the same. Observing the power-on state, the indicator lights on M1 and M2 are different. There are four indicator lights lit on M2, corresponding to ±5, ±33V, while there are three indicator lights lit on M1, namely ±5, -3.3V, lacking the +33V indication. The +33V voltage is not measured.
Therefore, it is judged that there is a high probability that M1 is malfunctioning. The M1 board from another normally used EUB-5500 machine is removed and replaced with the malfunctioning M1 board. After powering on, there is an image in the image area, and the machine recovers to normal. The repair manual mentions that MAP is responsible for smoothing and enhancing the image data transmitted from the EP board, and then converting this image data into a synchronous TV signal to be sent to the graphics card for display. Therefore, a malfunction of the MAP board directly leads to the inability to output images normally.

This information belongs to Rencheng Medical, please indicate the source when reprinting.