Before we replace anything on a Whirlpool, we run the module through a forced cycle. If the ejector sweeps and the mold heats, the module is healthy and the problem is upstream: water, temperature or the shutoff arm. If it does not cycle, we meter the module and its connectors. That sequence keeps us from replacing a good module because of a bad valve, which is a common mistake in rushed repairs.
We then check fill volume at the valve. Too little water gives small, hollow cubes; too much overflows the mold and freezes the cubes together into a sheet. We also look at the seal around the freezer, because a warm freezer is one of the top reasons a healthy module cannot do its job.
None of this needs a homeowner to open a panel. What you can do is write down when the problem started, whether it followed a filter change, a power outage, a move or a defrost, and which of the symptoms above matches best. That narrows the search before we arrive.