3B6 are one of our competitors.... They are an Italian spin off from PAT who also do vehicle weighing systems..
I designed the Timotex fork truck weighing system and also do my own.. Going off the pictures.. If it used to have 5 legs it would be the switched mode regulator... Going off the coil, cap and schlocky diode... It looks similar to mine...
I use the LM2576t-5... But it could be any... If this is blown apart the input voltage has been exceeded as they have inbuilt current shutoff.... If it is a switch mode regulator they normally have an input range of Vout+2 ~ 40v.... If your truck is a 50V truck there is a 60v version...
I have friends that know all about 3B6 systems, But I can't contact them until Monday!!!