Circuit boards are not designed to operate in humid conditions – but what happens when your circuit board is exposed to moisture? Is it possible to repair it? The sad but simple answer to this question is some water damaged circuit boards can be repaired some of the time. Once exposed to water, damage to your electronics begins within seconds – and the longer the exposure the worse the damage. Technically, it’s not really the water itself that is the real problem – but more on that later.
There are several variables you need to consider about whether your water damaged circuit board is repairable or not: Cost of circuit board replacement, Time exposed, Type of exposure, Delay- How long the damaged board sat before being repaired should all be considered.
How to consider the cost of replacement and availability of the circuit board? – If your industrial/commercial printed circuit board was cheap (less than about $250) it is usually best to replace it with a new board and dispose of the old one properly. If you cannot find a replacement then repair is your only hope.
Printed circuit boards consist of a laminate containing fiberglass for reinforcement and copper-clad epoxy, which forms the circuit’s wiring. PCBs are generally delicate and susceptible to water damage. Boards made from high-performance materials are more resistant to water damage which is why your board’s price point matters.
What type of water exposure will ruin my equipment? – Not all moisture exposure is the same. Circuit board damage can occur even from small amounts of moisture. This includes whether the electronics are splashed or spilled on, fully submerged, or even just exposed to high humidity.
Was the equipment exposed to liquid while power was applied? – This can be quite catastrophic in less than a second depending on the location of the exposure. The results can be equally as damaging if power is applied to a unit that has not been completely dried after it has been exposed to water.
- Splashed/spilled on – as you might guess, these boards will usually have the best chance of being repaired. A good professional cleaning may save these water damaged circuit boards. But, be warned, problems may surface later due to tiny bits of corrosion. More on corrosion later.
- Submerged – submersion of electronics in water is just never good and in mud, worse. Even if the equipment was not powered up at the time of exposure, it can be damaged due to the onset of corrosion. The longer electronics are exposed to contaminants, the more likely corrosion will develop.
- Humidity – Moisture is the enemy of electronics. But, moisture combined with the dust that typically coats electronics is the ultimate bad guy. The combination creates a nasty sludge coating on the boards inviting overheating and corrosion. These boards may be saved by a good cleaning.
So why is water not the real problem? – The answer is: Galvanic Corrosion, also known as two-metal corrosion. This is what happens when electronics (and they all have multiple types of metals) are exposed to water. Water is rarely just water – it contains minerals (known as dissolved electrolytes) such as calcium, magnesium, potassium, salt, and others. The minerals are what make the water conduct electricity and they are what cause the corrosion. If your electronics were exposed to true pure water, they would likely have very little damage.
How do you know if you have corrosion? – Often it is visible to the naked repairs for water damaged circuit board and looks like crusty deposits on electronic components such as contacts and connectors. Sometimes you may think your board looks fine and survived the water exposure. But if it is not working or developing intermittent problems, try removing the board from the unit and putting it under a microscope for a closer look. You may be able to see the crusty corrosion spots. Send it out for evaluation, cleaning and repairs. In cases where the electronics have been exposed to moisture for an extended period of time, corrosion can be catastrophic. If the circuit board has multiple layers, and corrosion penetrates into those internal layers, it may be undetectable.
What can you do about the corrosion? – For most businesses, a professional electronics repair facility is your best bet and the faster you get it there the better. Some of you may have repair capabilities in-house. The water damaged circuit board will need to be removed from the equipment and completely stripped down. Industrial sweep frequency ultrasonic cleaners (not jewelry ultrasonic cleaners) can sometimes be successfully used to remove the corrosion. Isopropyl alcohol can also sometimes be used to clean the board and dry it. Use of silica gel desiccants and rice is not advised. In many cases, re-flowing solder joints can reverse the effects of corrosion if it has not affected the inner layers of the circuit board.
What about repairs for your water damaged circuit boards? – To save you time, money and frustration we recommend sending the damaged circuit boards to an experienced professional industrial electronic repair company. This is usually the most time and cost-efficient way to get the board evaluated and repaired. Having a working spare board handy is important if you want to keep production going while the board is being repaired. And remember; only some water damaged circuit boards can be repaired just SOME of the time.
In addition to corrosion from direct contact with water, it can also occur from dust accumulation. Over time, dust containing hygroscopic substances can absorb moisture from the air, inducing corrosion. Over time, accumulated water can cause electrochemical reactions between the board components and the chemicals therein. Also, the electrochemical reaction might establish a connection between contrasting circuit elements, causing a short circuit, hence damaging your device. A short circuit can also occur if electric charges in the absorbed water find close circuits that shouldn’t be connected.
To overcome this, manufacturers coat boards with a conformal coating that creates a physical separation between the circuit and dust. While effective for dust protection, most conformal coatings don’t provide enough water resistance, and the board can still get damaged from direct exposure to water.
If it is out of warranty or if the warranty has been voided due to water damage, contact an independent industrial electronic repair center to find out if they are a good fit for your company and your particular repair needs. They should offer free evaluations for your damaged equipment and, if needed, a free quote for repairs (no bench fees!). They should also provide repair reports if requested and a good warranty of at least one year that covers both parts and labor.
About the Author: ACS Industrial Services is an independent industrial electronic repair center providing repairs for all types of industrial electronic equipment and most all manufacturers including circuit board repairs, logic board repairs, repairs for industrial power supplies, drives, servo motors, CNC equipment, encoders, monitors and touchscreens, test equipment, and much more. Rush Service is available and a comprehensive 2-Year Warranty covers most repairs. The customer service team is available to answer your questions and help solve your industrial electronic repair problems. You can reach them by calling 800-605-6419 or going to www.acsindustrial.com.