Repairing electronics makes you sensitive to decisions that stay invisible while a board is still a schematic.
At the repair bench, a missing label becomes time. A buried test node becomes risk. A protection decision becomes the difference between one failed part and a larger fault. An undocumented normal reading turns every measurement into a guess.
Those frustrations can become design inputs.
Give the measurement somewhere to happen
If a power rail matters during bring-up, it deserves a reachable and clearly identified place to probe. The same goes for reset, programming, major communications buses, and signals that split the fault tree in a useful way.
A test point is not automatically good design. It is useful when it answers a planned question.
Write expected behavior before the board arrives
It is much easier to rationalize a strange reading after power is applied than it is to define the expected state beforehand. A bring-up table should name the node, condition, expected range, instrument setup, and stop condition while the design intent is still fresh.
Treat the damaged component as evidence
A visibly failed component may be the source of the fault, but it may also be the victim of an upstream condition. Good troubleshooting asks what energy, control error, thermal condition, or surrounding failure could have produced the damage.
That same question improves design reviews: if this part fails, what else is exposed, and what evidence will remain?
Design for the next person
The next person may be a technician, a manufacturing engineer, a customer, or you six months later. Clear references, accessible diagnostics, sensible protection, and a real test plan reduce the amount of hidden knowledge required to make progress.
Repair and design are different disciplines, but the bench connects them. One shows where ambiguity costs time. The other has a chance to remove some of that ambiguity before it becomes hardware.