Hitachi EUB-5500 Maintenance

Fault phenomenon
The machine can't start normally. After booting, the progress bar goes to 1/3 and is executed. After shutting down, the same fault still occurs when the machine restarts.
 
Fault analysis
Hitachi EUB-5500 starts normally after opening the circuit breaker switch and pressing the boot button, the background indicator light of the control panel lights up, the display displays the reading progress bar, after the reading process of the progress bar is completed, the information that the system is starting will be displayed, and then the "Now setting system data. Please wait" start-up surface will appear, and then the ultrasonic system will enter the freezing state of two-dimensional mode after starting.
When the machine goes to 1/3 of the time bar after booting, it can be inferred that the failure of the machine system or PC part results in the phenomenon of machine crash. Firstly, the machine is rebuilt and then tested. After starting the machine, it shows that the reading progress bar is still 1/3 of the machine dead, eliminating the possibility of machine system failure. Hitachi EUB-5500 machine PC part motherboard, MAP board and PB2 board failures may lead to machine startup crash. After re-plugging the MAP board and PB2 board, start-up test, the same crash failure still occurs, eliminating the possibility of bad plate contact failure.

Repairing
After replacing the main board one by one, the MAP board, PB2 board and the main board are tested. After replacing the main board, the machine starts up normally and enters the two-dimensional working interface of ultrasound. The machine restarts several times and runs normally, and the machine troubleshoots are eliminated.