Fixing a broken monitor

I love fixing things! Well, I do when it works.

A couple of years ago I tried in vain to mend our electric shower which was cutting out due to lime scale build-up causing the element to overheat. I spent two hours unscrewing the unit, pouring vinegar into the various orifices and shaking vigorously. Plenty of scale fell out, but sadly on reassembly it gurgled and dribbled, but didn’t, well, shower. At the time it seemed worth a try, but I’ve learnt that showers are pretty complicated and fiddly to fix.

However, monitors are a different challenge. Earlier this year my second monitor, a Viewsonic VX912, failed. It started blinking on and off and after a while was mostly off, making it unusable. Getting by on one is OK, but slows me down quite a bit if I’m doing anything beyond simple web browsing or email-writing. I’ve had the screen for at least 8 years, so there was no chance of warranty fix/replacement. It would be nice if electronics was made to last a bit longer than single-digit years, but I guess manufacturers would like regular sales and consumers are often keen for an excuse to get the latest model. That thought crossed my mind; I was tempted to use this as an excuse to splash out on a new and higher-res model, but I also wondered if it might be fixable.

A quick Google shows plenty of articles and videos explaining how to fix monitors with the most common failure – blown capacitors. A capacitor is a simple electronic component which stores charge. They are used for timing circuits and smoothing out voltage irregularities. Along with resistors and transistors, they’re in almost every electronic device. When blown, cylindrical capacitors often show a bulging top and sometimes even leaking fluid – which I hear is nasty stuff and best avoided.

So, curious to see whether I could spot any “popped caps”, I unscrewed and prized apart the plastic clips on the back of the monitor. A few more screws to remove the metal back plate revealed this:

2013-07-15 12.21.35

Taking photos is essential when it comes to remembering how things go back together.

The cream-coloured board on the left is the power board (you can tell because the power lead socket is attached to it) and is often the source of such problems. The one on the right processes the inputs and connects to the display and front control panel. The capacitors are the black cylinders with silver ends, there’s also a large one sideways-on in the middle of the power board.

I checked all these carefully and found that there were indeed 4 of them “blown”. You can just about see how the ends are bulging in the next photo.

Blown capacitors with bulging tops.

Blown capacitors with bulging tops.

I’m reassured that the brown “goo” at the base is not in fact the toxic fluid leaking, but a glue used when machine-soldering the parts in.

I found 4 blown capacitors of 3 different types. I’ll skip the details, but the repair took about an hour and cost me about £7 for the new capacitors via Amazon. The monitor is now working normally again and hopefully will do many years more service.

Easy when you know how

It’s worth noting that I didn’t use much intelligence in this process. Although I studied electronics at school, I didn’t need any specialist knowledge to fix the monitor. OK, I do know how to solder, but this is probably easier than sewing, just with more chance of burning yourself. I don’t know exactly what the capacitors in question do and my diagnosis was limited to finding the ones which were bulging on the top. Had I done more research or had more knowledge, then maybe I could’ve swapped the capacitors for more robust or efficient ones. However, this would have required much more time and effort and probably required the manufacturer’s confidential circuit designs.

I’ve always been annoyed by waste and “disposable” electronics is an egregious example. I heard that a recent study showed a large proportion of discarded electronics could be simply and economically fixed. The researcher found many microwaves with nothing more than a broken fuse. Currently, electronics made in the far east, possibly under inhumane conditions, is far cheaper than the time of a local expert. This may change with global economics and as transport costs rise.

I saved myself perhaps £150 for a new monitor, but more importantly I had the satisfaction of fixing it myself, which is a great feeling. It’s also good for the environment, as the old monitor would have to be disposed of and electronic waste contains toxic chemicals making the problem trickier. Plus a new monitor would’ve had a far larger embedded carbon footprint than the small components I bought.

I’d encourage anyone with some broken electronics to have a good read through some of the many articles and videos on the web or see the dedicated IFixit website and get stuck in to fixing it yourself.

If it’s destined for landfill anyway, you’ve got little to lose by trying.

EDIT: The intermittent fault returned and despite further tweaking, this monitor is no more!

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