I have a EX120-3 digger. I can start it, but have no throttle control etc. Charge light and oil light come on momentarily when I start it, but thats it. No gauges and no control buttons work. I have checked fuses in the main panel behind the seat on top.
Did you check the ECU to see if the light is blinking?
Dont mean to sound dumb, I'm a farmer not a contractor. But what is the ECU, and where is it located. I've been to the machine for a look around. I found the throttle solenoid or mechanism behind the righthand rear door. Unplugged a plug and the engine nearly died. Plugged it back in, now everything is back to normal. Weird.
ECU = Engine Control Unit. I wish every time my Hitachi acts up it was that easy to fix.