3.2 Hardware Issue - PCB Assembly or IC Damage

Assembly issues can be difficult to identify. The best methods are:

  1. Visual Inspection: Perform a detailed visual inspection of the entire PCB. Check for missing components, incorrect component placement, and poor solder work. This step is time-consuming but essential, particularly for new designs.
    Note: The Paddle Ground cannot be visually inspected, a X-ray may be required to verify solder connections. Many random or unexplained behaviors are often due to a weak ground connection through the paddle ground.
  2. BOM Verification: Verify that all components placed on the PCB match what is specified in the BOM.
  3. Cleaning: Perform a thorough cleaning of the entire PCB to remove excess manufacturing residue. Certain solder flux residues can be conductive and create weak shorts which can cause unexpected operation.
  4. Solder Re-flow: Try to re-flow the solder on critical components manually, or the entire PCB (if possible) to see if operation is improved or changes. If operation changes after re-flow, a PCB soldering issue (i.e.: too much solder, too little solder, or incorrect solder baking profile) may be responsible for the observed issues.
  5. Q&A: Answer the following questions and consider the answers carefully. If you are experiencing issues where only certain PCBs exhibit certain issues, that is strong evidence of a PCB assembly issue.
    • Is the observed issue the same on each board produced, or different from board-to-board?
    • Do some boards work while others do not?
    • Is the issue localized to an individual build of PCBs (i.e.: previous manufacturing runs had no issues, and no changes to manufacturing have been made)?
  6. Failure Analysis: If the issue is only occurring on 1 board, or a very small number of boards, consider submitting the KSZ8081MNX device IC to Microchip for Failure Analysis.