Map the positions
List only results already known and identify front or rear positions. Give the display response for the affected area.
Do not jump to parts
A lit number does not establish that a zone receives power, and a dark panel does not prove a board failure. Assessment must consider the model and supply arrangement without repeated trip testing.
A useful distinction
On some layouts the controls group zones in ways not obvious from the glass markings. The complete model lets an engineer consider that design instead of assuming four identical independent heating circuits.