Error 20_3

Hello all, My lab has a used Eppendorf 5920R which is currently inoperable due to a recurring error message: "Error 20 _ 3 Electronics Fault Switch device off and back on after 20s" Power cycling resolved the issue on the first couple instances, but now we are in an endless loop. The user manual seems to indicate this is a temperature issue rather than an electronics fault issue. Does anyone know how to enter service mode and next steps in addressing this issue?