Copy it precisely
Keep letters, digits, flashing and accompanying symbols. A photograph is preferable to substituting a similar code found online.
Keep the physical symptom
Water inside, leakage and a programme stopping at a particular stage provide context. An engineer can use the model's information alongside inspection, rather than ordering a part from an unverified code list.
A useful distinction
The same visible code can be interpreted differently across product families. Preserve leading letters and digits and avoid replacing them with the name of a component suggested by a general search result.