You don't "crack the case" but open it carefully and repair the device like a service engineer.
”Cracking the case” (or “cracking open…”) is completely normal English colloquial usage for “opening the case”. It doesn’t imply that care is not taken.
Not that I think you should be trying to lecture people about language usage, when in your own first reply you said this, which is
not correct English, neither formal nor colloquial, and in fact led to confusion:
Just open the cover find powerful diode near output and put it out.
(FYI, to “put out” has several meanings in English, but none of them is “replace” or “remove”, or anything else that would apply here.) It’s fine to make language mistakes, we all do, but then don’t admonish others for what in fact aren’t even mistakes!