How Is Board-Level Fault Diagnosis Done?

Success in board-level repair depends on systematic diagnosis, not random part swapping. The general flow is:

1. 1
   Visual inspection

   Burns, bulged capacitors, cracked joints, corrosion.

2. 2
   Verify supply rails

   Short/open checks and voltage measurement.

3. 3
   Section-by-section measurement

   Power stage, driver circuit, control and measurement circuits.

4. 4
   Test under load

   After repair the board is verified with heat and current profile.