IRB 340 SMBUS error

Im getting an error “SMBUS unit at address (#) is not responding” It is multiple addresses (33, 35, 39,etc). Anyone know what causes this?

SMBus is communication between the main computer and other units of the power supply system in a S4C+ controller.

Having an error on all addresses is more than likely an issue with the main computer itself or the cabling/connectors of the SMBus.

Which cables would I have to check?

see attached extracts from the manuals
SMBusCircuitDiagram.pdf (110 KB)