Last Updated on April 15, 2023 by Dave Farquhar
Do AC adapters go bad? The answer surprises many people, but the answer is yes. The question, then, is how to lengthen their life expectancy and what to do if they do eventually go bad.
Why AC adapters go bad
AC adapters, also sometimes called AC power adapters, convert electrical power from household current to something that small devices can make better use of. When converting AC power to a lower voltage of AC, there’s not much involved beyond wire windings. So those devices, properly called transformers, often last decades. The only thing that causes a transformer to go bad is the windings burning up.
But today, most adapters actually convert household AC to low-voltage DC. Converting AC to DC is a more complex process involving more components. More components mean more things that can fail, and it only takes one of them going bad to make the adapter stop working. Then the device quits working because it’s not receiving any power.
When any electronic device stops working, I always suspect the AC adapter first.
A qualified technician can take the adapter apart, locate the bad component and replace it. But it’s usually not worth the effort when mass produced AC adapters only cost a few dollars. The part may cost $2, but it may take half an hour to swap it in to save a $10 adapter.
When an AC adapter goes bad, it’s cheaper and easier to replace it than to try to fix it. More on that in a minute.
How to lengthen the life expectancy of an AC power adapter
AC adapter components go bad from heat and use. The adapter still uses some electricity even when nothing is plugged into it. So the best way to prolong your AC adapter’s life expectancy is to unplug it if you’re not using it. Sometimes this isn’t very convenient. One way to make it more convenient is to use an energy saving power strip. Energy saving power strips cut the power to outlets when other devices are off. Using an energy saving power strip on a TV or a computer lengthens the life of AC adapters that power accessories plugged into them.
Usually, an AC adapter lasts years regardless. Unplugging it when not in use will probably prolong its life expectancy beyond its usefulness. That’s not a bad thing.
So if you can unplug it, or let a power strip cut the power for you, when you’re not using the device, the AC adapter will last much longer.
What to do when an AC adapter goes bad
When an AC adapter goes bad, you need to replace it. I’ve written about that before. If you need machine-specific advice, I have advice for Nook devices and Atari 2600 game consoles. Frequently, the device it plugs into will still work just fine once you replace the adapter.
You can’t do much about the quality of the adapter that ships with your devices. But when buying replacement adapters or additional ones, avoid buying the very cheapest adapter you can find. You can get an adapter for 99 cents online, but that doesn’t mean it’s a good idea. Pay a few dollars to get one from a reputable source, and look for the UL logo on it, which indicates Underwriters Laboratories evaluated the device. This gives you a better level of assurance of the adapter’s safety and potential longevity.
I frequently buy AC adapters online. I’m just careful about what I’m buying. If you need something today, big-box consumer electronics stores or stores like Batteries Plus are a reasonable source local to you. Or, here’s an offbeat source. Most thrift stores have a box of stray AC adapters somewhere in the store. If you find that box and sift through it, you may very well find something suitable, and you’ll probably only pay a couple of dollars for it.
David Farquhar is a computer security professional, entrepreneur, and author. He started his career as a part-time computer technician in 1994, worked his way up to system administrator by 1997, and has specialized in vulnerability management since 2013. He invests in real estate on the side and his hobbies include O gauge trains, baseball cards, and retro computers and video games. A University of Missouri graduate, he holds CISSP and Security+ certifications. He lives in St. Louis with his family.