How to Clean a Circuit Board - A Q Source Guide

There’s some common advice our parents might have shared early on that can see us through — and help avoid — many repair projects: you’ve got to take good care of your things.

So simple, yet so true. And nowhere is it truer than in the world of electronics, where the slightest speck of dust or the dreaded creep of corruption can halt operations in a heartbeat, sometimes for hours or even days. And nowhere in the electronics world is it truer than with circuit boards, which are well-documented, highly sensitive dirt-mongers.

That’s why it’s essential to stay on top of your circuit boards with a maintenance program and also to know how really get down and dirty when the need arises, which it will. Here’s a valuable guide from worldwide distributor Q Source that includes instructions for accessing your computer’s circuit board, spot-cleaning the circuit board with isopropyl alcohol and compressed air, and removing corrosion with baking soda. For ESD-safe cleaning, we recommend the MicroCare Circuit Board Cleaning Station Kit.

1. Taking out the circuit board

First and foremost, shut down the computer and unplug it to avoid risk of electrocution or damaging any components of the device’s hardware. Then, before you access the circuit board, do a preliminary cleanup by inserting the nozzle of a canister of compressed air into the computer’s fan exhaust ports.

It’s important to keep the canister upright when you spray, so you may have to be working from below the device — most likely from your knees when working on a desktop computer, or holding a laptop high enough to keep the canister upright. Spraying the canister upside-down runs the risk of freezing the components, as does spraying for too long, so also be sure to use short, quick bursts of air.

Once that’s done, you can use the appropriate screwdriver head to unscrew the back of the central processing unit, or CPU. Slide back the side panel to reveal the circuit board, which also may require a screwdriver to be removed. Then you are ready for a spot-clean.

2. Spot-cleaning a circuit board

Pour some high-grade, 95 to 100% isopropyl alcohol into a small bowl or dish. Wet a small brush such as a toothbrush or a cotton swab with the alcohol and give the board a thorough scrubbing, coating all of both sides of the circuit board with alcohol but avoiding leaving puddles in your wake.

Concentrate on any particularly dirty, grimy areas, but be gentle and let the alcohol do the work. It should dislodge any larger debris without forceful scrubbing, and you can tackle corrosion or super-grimy spots in the next step. Use both ends of a cotton swab for any hard-to-reach spots, dabbing one end in the alcohol and using the dry end to soak it up when finished.

Finally, use the compressed-air canister to blow-dry the circuit board and clear away any excess debris after scrubbing. Finally, to be on the safe side, let the board air dry for another 15 to 20 minutes before replacing it back into the computer. If, however, you see evidence of corrosion or debris that hasn’t come off yet, move onto the next step.

3. Removing corrosion from a circuit board

For this step, you’ll have to add a pencil eraser to your growing pile of circuit-board cleaning tools. Lightly rub the eraser tip on any corrosion or debris that did not previously come off in earlier steps, blowing away the remnants of your work with the air compressor.

If this still does not get the job done to your satisfaction, the final step is to mix a solution of baking soda and water to form a watery paste. Fully saturate a cotton swab or your small brush with the paste and liberally apply to the affected areas.

Let the circuit board air dry in a safe place for 24 hours, leaving the paste on the corroded spots, and then dab your brush or swab with more high-grade isopropyl alcohol and gently scrub the areas clean. This should do the trick and if it is indeed corrosion, the process will almost certainly lead you to a corroded battery that needs replacing.