This devices work with high temperature.
The solderings are made with lead-free soldering paste, and are verry breakable.
Just the phisical manipulation of the board can cause detachament of one ore more chips.
The only solution is cleaning inside the casse with copressed air, and whe they are at normal temperature.
Otherwise you wil cause temperature stress.
If the chips get loose, unfortunatly you must resolder, or change, in any case you need special equipment and skils!