If it is dry or dried up, and not spreading - then no need to do anything.
Just maintain nice growing temperature, and a safe level of lighting (not too bright unless the orchid has been sun-hardened ...... but even sun-hardened will have upper limits), and nice gentle air-movement.
Most welcome Karl. From the appearance of the orchid from the photo ------ it certainly appears dry at those patch regions. Your orchid looks just fine.