PCB Outoor RZQ140C7 faulty.

hello all, who can tell me what value the resistor circled in the picture, namely the R 751, in essence, the wire controller gives me the error U4, "between UI and non-EU dialogue."
The machine in question is a RZQ140C7 channeled. I measured the supply voltage input and is present.The form attached is the outdoor unit. I tried online but have not found anything.
Thanks to all.

Is the resistor value not shown on the resistor?

no it is not shown...
I'm sorry that the customer pays € 1200 for a simple resistance