toshiba E04 fault

[langy]

Got a Tosh split compact cassette (indoor RAV562 ATE, outdoor MUT-E) keeps randomly showing E04 and shutting down.
The outdoor (first) AND indoor pcb's have been replaced, but it's still happening.
I've just been scrolling through a technical manual provided by one of you fine fella's and it mentioned..... fault code E04= Indoor unit receives no signal from outdoor, CAN "include klixon on 560 digital inverter" and says check by measuring voltage between capacitors.
Can anyone enlarge on that?
OR

Can anyone help please?

[langy]

OK does anyone know if the system was running slightly short of refrigerant and the klixon(if it has one) on the compressor tripped......could that come up as an E04 fault?????

[Davey 2 Pints]

OK does anyone know if the system was running slightly short of refrigerant and the klixon(if it has one) on the compressor tripped......could that come up as an E04 fault?????

Yes, E04 on this system will result from an open circuit klixon.
There's every chance the quantity of gas in the system is the problem or a restriction in the refrigerant flow around the system could also be an option.