Category Archives: Technology

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!

Your passwords aren’t good enough

In 2009 a list of 32 million plain text passwords was exposed for the online games service RockYou.com.

So what? You probably weren’t signed up to RockYou.com, so why should you care?

It should go without saying that your passwords are valuable to criminals, either directly for identity theft, or as part of a large collection of compromised accounts that can be misused en masse in more subtle ways.

OK, but these were other people’s passwords, so why is it a problem?

Firstly, this huge list helps password crackers to guess what kinds of passwords people use. Secondly it showed that most people’s passwords are rubbish. By rubbish I mean that they can easily be cracked. Most of the passwords were short, contained common words and many them were not unique, meaning that they were so obvious that more than one person had chosen the exact same password.

Other leaks involving high-profile sites like Yahoo! and LinkedIn contained “hashed” passwords. These can only be transformed into plain-text by repeatedly trying possible passwords. A human wouldn’t get very far with this, but computers excel at the task. What’s more, password cracking technology has been advancing apace, with expensive, yet home-made, machines able to try 6.2 billion passwords a second. This kind of “brute-force” approach resulted in many of those leaked hashed passwords being cracked, leaving the accounts at the mercy of the crackers.

Worse, many LinkedIn and Yahoo! users had been using the same password on multiple sites, meaning that when the leak occurred they had to hurriedly change all their passwords.

What can a careful Internet user do?

We can’t control the security measures used by all the websites and services we use. In most cases we probably can’t even assess if their procedures are good enough.

What we can do is limit the potential damage. There are a few ways to do this:

  1. Use a unique password for every website you visit.
  2. Use strong passwords that are difficult to guess, even with powerful computers.
  3. Change passwords regularly and especially after using any untrusted networks (wireless or otherwise).

A strong password:

  • Is at least ten characters long
  • Contains only a randomly-generated combination of mixed-case letters, numbers and punctuation. (If you need to enter the password on a smart phone, it may be best to make it a little longer, but avoid some punctuation like curly brackets).

More advice can be found on Healthy Passwords or BBC Webwise.

But strong passwords are hard to remember!

If remembering lots of really tough passwords sounds a bit of a pain, I have some suggestions to make it easier.

Firstly there are a number of free applications available which make creating and storing your passwords simple and secure.

For example, KeePassX will run on Windows, MacOS X, Linux or a smart phone. When visiting a website you can simple copy and paste your unique, long, super-secure password from your encrypted KeePassX database into the website without having to remember it. I also use it to store personal details like my National Insurance and passport numbers.

You’ll need to take the small file with you or have it shared on a cloud-service such as Dropbox. Remember that this file is encrypted, so while you shouldn’t make it public, it will still be pretty secure should ne’er-do-wells get hold of it.

Your encrypted database can be secured in a number of ways. Firstly, a key file (perhaps kept on a USB stick or CD), a really strong password, or both.

So you still need to employ the grey cells to keep your information safe. Yes, but remembering one strong password is easier than remembering fifty. If you still find this impossible, it’s probably better to write it down somewhere inconspicuous rather than resort to a weak password you can remember. Most password cracking attempts come from online sources rather than the people around you.

So writing 9.-Xhd5u@y in the back of your diary is probably more secure than having Bicycle2 only in your head.

An alternative to passwords

If that still sounds too hard, you may appreciate the suggestion of the sometimes-serious webcomic XKCD, which suggested “pass-phrases”. Four randomly-chosen words are easier to remember and harder for a computer to guess than a medium-length string of random characters. XKCD’s example was:

correct horse battery staple

But as long as the words really are random, it’s a good pass-phrase. So no song lyrics or famous quotes! You can bet they’ll be in the crackers’ lists.

After what I’ve read on this subject I’m in the process of improving all my passwords. I encourage you to do the same!