The Computer Corner: It has happened again

The Computer Corner: It has happened again

It has happened again, unfortunately. This time it started when a client called me several times over a week-long period reporting an increasing number of troubling problems with a brand new laptop.


First, she had difficulty even getting into her laptop because the fingerprint reader stopped recognizing her digits. I asked the obvious question about whether or not she had just put on hand lotion but that was not the problem. Next, when she tried to make a Zoom video call the onboard webcam would not start. She tried to participate in the call without using video but the sound stopped working too. The next thing she noticed was that the touchscreen no longer responded to her touch. Such a series of seemingly unrelated hardware failures was hard to explain.


Realizing this brand new laptop could be a lemon and was apparently disintegrating right before her eyes, she wisely decided she should back up her important data files before anything else went wrong. Unfortunately, the computer would not recognize any USB hard disk or flash drive. That is when she called me.


This weeks-old laptop seemed to be almost dead, but luckily this client still had the clunky old laptop she was replacing, so we decided to fall back on it. The old laptop was retrieved from the closet. The client swiftly unplugged the power cord from the new laptop and was about to plug it into the old laptop before I screamed “STOP!!!!” You should never ever use a laptop power cord that belongs to a different laptop.


She said, “They’re the same,” to which I responded, “NO!!!!” If you use the wrong power cord with the wrong voltage it could damage the finger print reader, then the webcam and sound could stop working, then the touch screen might stop working, then the USB ports could be burned out, then…then…then it dawned on me.


She had been using the wrong power cord. When she purchased the new laptop it was too much trouble to crawl under the desk to plug in the new power cord so she had just used the cord from the old laptop with her new laptop. When I compared the labels on the two power cords, I found that the voltages were different. “But the plug fit,” the client wailed. The fact that the plugs fit does not matter. The voltage(s) and amperage(s) supplied by the power cord do matter. Even a small difference in voltage can be really bad news.


Most of the time if you use the wrong laptop power cord, it simply does not work or it only fails to charge the battery, all without doing permanent damage to anything. But using the wrong power cord with the wrong voltage can, in some circumstances, utterly destroy a laptop. In this case it appears this is what happened to my client, all because she assumed that using a different power cord would not make any difference. Sadly, the difference of a few volts cost her several hundred dollars.


Charles Miller is a freelance computer consultant, a frequent visitor to San Miguel since 1981 and now practically a full-time resident. He may be contacted at 044 415 101 8528 or email