Issue 264: A Case for the DIY Electronics Fix

Most of today’s expensive electronics systems are engineered to be left alone—meaning, the manufacturer doesn’t want you opening, servicing, or tweaking the products on your own. But that doesn’t mean intelligent, inquisitive engineers shouldn’t give modern electronics gadgets a good hack. The rewards tend to outweigh the drawbacks. As Steve Ciarcia argues in Circuit Cellar 264 (July), you stand to learn a lot by looking inside electronics systems, especially broken ones. Even if you can’t fix them, you can pull out the components and use them in future projects.

In “Fix It or Toss It?” he writes:

No prophetic diatribes or deep philosophical insights this month. Just the musings of an old guy who apparently doesn’t know when to throw in the towel. Let me explain.

I have a friend with a couple LCD monitors he purchased about two years ago. Perhaps due to continuous duty operation (only interrupted by automatic “Sleep mode”), both were now exhibiting some flakiness, particularly when powering up from “sleep.” More importantly, if power was completely shut down, as in a power failure, they wouldn’t come back on at all without manual intervention. He asked if they could be repaired or must they be replaced.

Since I remembered something about a few manufacturers who’d had a bunch of motherboard problems a while back due to bad electrolytic capacitors, I suspected a power supply problem. Of course, agreeing to look into the problem and figuring out how to get inside the monitors was a whole different issue. Practically all of today’s electronics are not meant to be opened or serviced internally at all. Fortunately, my sledgehammer disassembly techniques weren’t so bad that I couldn’t reassemble them. In the process, I found several bulging and leaking capacitors on the power supply board. After replacing the capacitors, the monitors came right up with no problems.

Power supplies just seem to have it out for me. Recently, I had a wireless router stop working and, after a little diagnosing, I determined that its power supply (an external wall-wart) had failed. While hardly worth my time, I was curious, so I cracked open the sealed case to see just how complicated it was. Sure enough, replacing one scorched electrolytic capacitor and gluing the case back together put me back in business.

All this got me thinking about the relative value of various electronic devices. What is the replace/repair decision line? These $200 high-tech electronic LCD monitors failed because of $3 worth of old-tech components that I was fortunately able to fix. It took time to do the repair that has some value, but it also takes time to shop for and purchase a replacement. There must be better monitors these days for the same price. Should I have told him to toss them and use the opportunity to upgrade?

It’s interesting to consider the type of person who repairs stuff like this (being an EE with a fully equipped lab doesn’t hurt either). I mean, I do it primarily because I like knowing how things work. Okay, so I’m getting a little carried away after fixing a couple burnt capacitors, but there’s still an incredible sense of satisfaction in being able to put something back together and having it work. Since I was a kid, dissecting circuits and equipment helped me understand the design choices that were made, and my curiosity naturally lead me to engineering.

Now, I recognize that people like me who repair their own electronics for curiosity or adventure are very much in the minority. So, what about the average person with a failed piece of $200 electronics? For them, the only goal is getting the functionality back as soon as possible. Do they go to a repair service where it takes longer and involves a couple trips? Worse yet, some things just can’t be repaired, and the bad news then is having both the repair “inspection” cost and the replacement cost. I’m guessing that in 99% of typical cases, the no-brainer decision is to toss the failed unit and buy a new one—without ever giving me a chance to tear it apart and play with it.

Let’s face it. Taking modern equipment apart to make even simple repairs is next to impossible. The manufacturers use every trick in the design book to minimize the cost of the goods. This means leaving out features that might make end-user repair easier. Cases that snap together (once)—or worse, are heat-welded together—are cheaper than cases with screws or latches. Most board electronics are custom-labeled surface mount devices, everything uses custom connectors, and the short cabling between boards has no slack to swing out subassemblies for access, and so forth. You couldn’t even fit a scope probe inside most of this stuff if you tried. Sure, some manufacturers do still put component reference designators in the silkscreen, but I suspect it’s so they can repair subassemblies on their production line before final assembly, not make it easier for me to poke around.

Anyway, like I said, there’s no prophetic conclusion to be drawn from all of this. I fix stuff because I enjoy the challenge and I usually learn something from it. Even if I can’t repair the item, I usually keep some of the useful components and/or subassemblies for experimenter one-off projects or proof-of-concept prototypes. You never know when something in the junk box might prove useful.

Circuit Cellar 264 (July 2012) is now available on newsstands and at the Circuit Cellar Webshop.

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