10 minute read

Over the years, I’ve encountered quite a lot of tech problems, as someone who knows a lot about computers, writes software for a living, and has worked in IT support does. Most problems are caused by a simple misconfiguration of some kind, or occasionally a software bug. But some are strange and perplexing, to the point that sometimes you don’t know where to begin.

I’ve noticed many patterns in these kinds of issues over the years. Some of these patterns both frequently turn out to be the problem and are cheap and easy to rule out. So if you don’t know where to begin when dealing with a strange problem, you should check for these problems right away.

Needs a restart

We’ve all heard “turn it off and turn it on again,” but it’s a cliché because it really does work! In fact, rebooting often solves the biggest, weirdest, most confusing problems. (This makes sense from a technical perspective: restarting a device works when the software or hardware has somehow gotten into a temporary state it wasn’t designed to be in, which means almost by definition it’s going to behave unpredictably.) Most importantly, restarting usually costs nothing and takes only a couple of minutes.

Don’t forget that you can do this with anything electronic, not just computers or mobile devices. If your internet connection is acting up, restart the router. If your keyboard is acting up, unplug it from the computer and plug it in again.

Tip: On modern computers, always choose the “Restart” option rather than literally turning the computer off and turning it on again. Shutting down a newer device often doesn’t actually shut it down; instead it “hibernates” and stores some of its current state on the hard drive so it can start up more quickly when you turn it on again. That’s usually a good thing, but it means simply powering off and powering on again won’t help if you’re having a problem.

Bad cable

Cables can easily be plugged into the wrong place or come loose, and they tend to wear out faster than the devices they come with: they get stepped on, yanked, thrown, and bent, and many of them are made pretty cheaply to begin with. On top of that, it’s common to reuse an old cable when you get a new device, so the cable might actually be much older than you realize.

Some real issues I’ve seen with cables:

  • Someone’s mouse wouldn’t work because it had been plugged into an Ethernet port. (Believe it or not, the old-style rectangular USB plugs fit almost perfectly into the center of an Ethernet port. It doesn’t feel quite right, but if you’re distracted and plugging it in without looking, you can easily not notice. I have done this myself multiple times.)
  • I got a new audio interface to record some music on the computer, but the computer wasn’t seeing any audio. After two hours of playing with levels, reinstalling drivers, and trying various other tests and fixes, I discovered I had plugged the “line in” cable into the “line out” jack behind the computer.
  • My monitor went all green. After determining it wasn’t the monitor, I bought a new graphics card, only to discover that when I plugged the new card into the old cable, the monitor was still all green. Yeah, it was the $5 video cable that had failed.

When a device stops working, first check to make sure it’s still securely plugged in to the right jacks on both ends. “On both ends” probably sounds like I’m being facetious, but on multiple occasions I’ve watched both myself and other people forget that cables have two ends, both of which could be the problem!

If that doesn’t help, try a different cable. You might already have a spare cable of the right kind – don’t forget to check other devices you could borrow one from as well as the box of cables in your closet. Even if you come up empty and you don’t have a friend around who has one you can borrow, it’s probably worth buying a new one to see if it helps. Cables are cheap compared to almost any other hardware replacement or repair you might try, and you can probably find a use for the new one later if the cable doesn’t turn out to be the problem.

Note: Cables inside devices wear out frequently, too. For instance, an apparent hard drive failure could be caused by thermal stress on the cable (the cable comes loose or becomes damaged after being heated up and cooled down repeatedly). Laptop monitors also fail this way with some regularity; in the most common design, a cable runs between the main body of the computer through one of the hinges to the LCD panel, which makes it quite vulnerable to pinching or wear as you open and shut the lid thousands of times, probably sometimes not particularly carefully! Unfortunately, this is more of a fun fact than a useful troubleshooting tip, as internal cables are rarely user-serviceable, and even when they are, it’s no simple matter to get the appropriate part and try it out. (Proprietary parts are often ludicrously expensive as well. When I added a second hard drive to my last laptop, I had to pay over $50 in 2015 dollars for an appropriate hard drive cradle – which was a simple aluminum frame probably worth 5 cents in scrap value. And it didn’t even come with the screws needed to attach the drive.)

Malfunctioning flash memory

Many portable devices use microSD cards or thumb drives to store data. Most of these are made at cut-rate facilities with lousy parts. At the best of times they have a short life expectancy, and they fail often and in unpredictable ways. I’ve even heard of counterfeit flash memory lately – the card will say, e.g., 32GB on it, and will report it has 32GB free when you plug it in, but it actually stores only 8GB and silently overwrites the old data with new data when it runs out of room! When your portable device starts being unable to reliably read and write data because the card has failed, it may stop working entirely, give a bunch of cryptic errors, or do even weirder things.

If any device that relies on portable flash memory is acting up, grab a new card from your closet or from the nearest convenience store and see if that solves the problem. Even if you have to buy one and it doesn’t work, chances are good you’ll need another one for a different device soon enough, so the cost should be minimal.

It’s also worth paying a few extra bucks for your next card to head this problem off from the start – pick a brand you recognize and check that it’s rated for a reasonable number of write cycles and a faster read/write speed. But even good cards will fail eventually.

Full hard drive

When the hard drive of a computer or mobile device gets close to full, writing data to it becomes markedly less efficient since data will often have to be shuffled around and rewritten to make room, so many devices will start to slow down noticeably. This usually happens gradually since the drive usually fills up gradually, so you might not notice it happening until one day you suddenly realize your device is unreasonably slow. And if the drive gets filled into the 99%+ range, write requests will start getting rejected due to lack of space and all sorts of things will stop working entirely; not being able to save anything will break a lot of software!

Modern drives should ideally be kept no more than 80% full for best performance and longevity. It’s not like your computer is going to explode if you keep it at 85% – you probably won’t even notice – but if you’re cleaning things up, try to get it down below 80%, and if you regularly have trouble keeping it lower, it may be time to upgrade.

Checking if the drive is full is free and takes seconds, so I usually check this first when someone complains their computer is slow. If it does turn out to be too full, all major operating systems now have tools to help you find what’s using all your space, and if you don’t find anything you can delete, you can pick up a cheap external hard drive. (Just make sure you have a second copy…backups are always important, but the commodity external drives seem to me to be especially unreliable, and at a minimum, they’re much easier to lose or break than an entire computer.)

Outdated software

Software updates can cause problems just as easily as fix them, but if you already have a problem, your chances of improving it by updating are decent, and it’s usually a good idea to stay on top of updates anyway. Updates are normally free nowadays, too.

If the problem is with a hardware function on your PC, like your laptop’s wifi connection or monitor, it’s also worth making sure the driver for that device is up-to-date. Driver updates are often pushed automatically through the same mechanism as your operating system nowadays, but not always. (Drivers are just pieces of software that tell the computer how to use the hardware.)

Bad battery

This one happens less often than some of the other problems I’ve listed, but depending on the device, this can be a cheap and simple thing to check. Failing batteries often provide inconsistent power to electronic devices, which causes all kinds of strange problems.

Here’s possibly my favorite tech support story. A friend called me and was having issues with his laptop. He dropped it off at my house to troubleshoot for a while; I worked on it for an hour or two while doing something else (I can’t remember the exact problem, but it required me to frequently let things run for minutes at a time), and I wasn’t getting much closer to a solution. Then, all of a sudden, it started working fine, and no matter how much I tried I couldn’t reproduce the problem again. I shrugged and gave it back to my friend, figuring it was fixed. He took it and left, and then an hour later he called me and it was broken again.

So we decided to take a look at it again. This time I went over to his house. With him sitting at the computer, he showed me the problem again – multiple times in a row. I sat down at the computer and did the exact same thing, and it worked.

We gave each other the “am I going crazy!?” look, and then I suddenly saw the common factor between these two troubleshooting sessions: right before it started working, the battery had run low and we had plugged the computer in. Sure enough, a new battery fixed the problem.

In general, if you have a device with a removable battery that can also run on AC power, and you’re started to run out of ideas on a very strange problem, you can try taking out the battery with it plugged in and see if that improves its behavior at all. On newer devices with batteries that can’t easily be removed, software is usually available that can check the health of your battery. If it shows the battery is failing, it might be worth doing a replacement, depending on how expensive the battery is (if it’s unlikely this is the issue and the device is on its last legs anyway, it’s probably not worth trying given the relative rarity of this issue).