What To Do When You Need To Troubleshoot Your PCBAugust 9, 2021
Each printed circuit board (PCB) is created specifically to the designer’s specifications. However, accidents can cause the board to be faulty, or oversights could’ve occurred during the production process. At times, it may be necessary to perform maintenance on a flawed circuit board. To fully understand what to do when you need to troubleshoot your PCB, it’s vital to know the complexities of the board.
PCBs used to have a complex manufacturing process that consisted of detailed wiring on specific points. The circuits were often left exposed and vulnerable to damage. The process has since advanced to what PCBs are today.
Diagnosing the Problem
You must determine the source of the problem before you can begin fixing the issue. Diagnostic work on a PCB that isn’t working should go as follows:
- Identify the problem with a VI instrument. Alternating the voltage will identify the pin count.
- Pinpoint the location of the issue. This requires examination at a microscopic level.
Gathering the Supplies
If you want to fix the PCB, you’ll need the following materials.
- Dental picks
- Circuit frame
- C-clamps (small)
- Orange sticks
- Soldering iron
- Kapton tape
- Exacto Knife
- Isopropyl alcohol
- ESD-safe surface for cutting
Following the Proper Steps
After gathering the supplies, follow these steps when you need to troubleshoot your PCB.
Step 1: Use the isopropyl alcohol to clean the affected part of the PCB. Once it’s clean, use compressed air to dry the alcohol.
Step 2: Use the exacto knife to remove the damaged pad.
Step 3: If you see any burnt laminate around the area, make sure to remove it.
Step 4: Remove any lingering solder mask with a dental pick.
Step 5: Use compressed air and isopropyl alcohol to clean and dry the area.
Step 6: Prepare the conductor area with a proper solder alloy where the replacement alloy will go.
Step 7: Choose your new conductor with the appropriate choices on the circuit frame. Remove the selection from the circuit frame with an exacto knife.
Step 8: Cover the spot on the new conductor that will face the old trace with an alloyed solder. Then, prepare your epoxy. Prepare the epoxy in small batches because it’s only good for around 45 minutes. Apply the epoxy to PCB. You can speed up the process by placing it in open air or curing the joined pieces in an oven.
Step 9: Use Kapton tape to set the new conductor into place.
Step 10: Clamp the new pad and allow it to cure. When it’s finished, remove the clamp.
After these steps, it’s best to conduct a brief inspection of the electrical continuity. PCBs are in the best care when skilled technicians handle the assembly and repairs.