How to fix a broken screen on a Nexus 4

Posted in Gadgets, Howto, Tech on June 24th, 2014 by Andy
Broken glass

Not really what you want to see…

A couple of weeks ago I dropped my Nexus 4 and cracked the screen. The touchscreen was still working ok, but I went ahead and replaced the screen anyway. Here’s how…

On the Nexus 4 the screen is bonded to the touchscreen digitiser behind it, so unless you want some major hassle it’s easiest to just replace the screen and digitiser as one unit. You can pick up kits on Ebay to do this, mine cost about £45 and included screen, digitiser, tools and the frame (which was nice, as my screen frame was getting a bit worn).

I followed this video. The only things I would point out are that it’s easier to remove the SIM card holder first. Doing this makes it easier to pry the back shell off. If you’re replacing the whole screen unit you also don’t need to worry about heat the screen and seperating the components. Don’t forget to transfer over all the fiddly bits like volume buttons and the headphone jack from the old frame to the new one.

It’s not at all hard to do, with the right tools it’s just a matter of working carefully and methodically. My phone is good as new.

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Should I buy refurbished appliances and gadgets?

Posted in Gadgets, Tech on May 19th, 2014 by Andy

Yes you should, and the reason why has more to do with bathtubs than you might have expected. Not only are refurbished goods a lot cheaper than brand new ones, they’re actually better. Meet the Bathtub Curve:

The Bathtub Curve

Those of us who are paid to dip our toes into reliability engineering will be familiar with this graph:

The curve shows decreasing probability of failure over the short term

Engineers developed the bathtub curve from analysing the failure rates of huge numbers of machines. Basically it shows that things are highly likely to fail early in service (due to manufacturing defects, etc), then settle in and run reasonably reliably until they start to wear out and fall apart. Now, in real life nothing fits the nice smooth curve exactly, but in general it holds true. That’s why everything you buy comes with a warranty, manufacturers expect a certain percentage of their stuff to die straight away.

The bathtub curve, showing the lower chance of failure after the initial period

After a short period of use the chance of failure drops substantially

Now, when stuff  develops a fault in early service, people send it back to the manufacturer who often sends out a replacement. All good so far. The manufacturer repairs the original device and sells it on as a refurb for a substantial knockdown. My whole point is: having been in service for a short time and having already surfaced any problems, the refurbed machine is now less likely to conk out than a new machine. You’re now getting a machine that will be more reliable and costs less, and you’ve still got a warranty if it does go wrong again. Why buy anything brand new if you could get a better one for less? The worst wear and tear I’ve seen on any refurbed tech or appliances are some minor cosmetic scratches, which you’ll have on your new gizmo within a few weeks anyway.

I’m interested, hook me up.

Plenty of big companies have a refurb scheme. If you’re in the UK check out:


PC World

eBay (don’t be afraid of this one, lots of people run small businesses through eBay where they sell on the refurbed units from bigger suppliers)

Amazon refurbished

John Lewis Swindon outlet

Marks and Spencer outlet

Currys household applicances

Currys computing

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How to make a Raspberry Pi media centre

Posted in Computers, Gadgets, Howto, Linux, Tech on August 21st, 2013 by Andy
A man wearing a t-shirt printed with "couch potato" and juggling several remotes.

We’re doing important stuff here.

I built a media centre PC a few years back and I’ve been happy with it ever since. It’s been running XBMC, which is an awesome free media centre package. But I reckon it’s time to get some Raspberry Pi in my front room.

Why Raspberry Pi?

  • It’s cheap!
  • It’s fanless (ie: silent)
  • It can push out full-HD video
  • It’s got HDMI (including sound and CEC) so only needs one connection to my TV.
  • It’s very low-power so can run constantly. So no waiting for it to boot up.
  • Customised XBMC builds are available for it, and are well supported.
  • I keep all my media on my network, so my media centre box doesn’t need any storage
  • It’s so small I can just velcro it to the back of the TV, removing a whole box from my TV stand.

How much will it cost?

  1. Raspberry Pi Model B: £32
  2. Plastic Case: £5ish

Which is less than the parts of my old machine are worth on Ebay. Ka-ching!

You’ll also need a power supply that can put out 5V on a micro-USB (I’m using a Kindle charger) and an SD Card to install the OS onto. I had both of those knocking about, which saves money. I also plugged my old media centre’s wireless keyboard into the Raspberry Pi’s USB port, just in case. In practice we can control XBMC with a tablet or smartphone over our home network, but a keyboard and trackpad can be handy during setup. You could ditch it after that and save a bit of power. There’s always SSH from another machine if you need to do anything fiddly.

Enough waffle. How do we do it?

Pretty simple, plug your SD card into a computer (one running Linux is easiest IMO), and download Raspbmc. Raspbmc is a ready-rolled bundle containing a very minimal Linux operating system and XBMC. Once you’ve downloaded the archive, extract it and run the installer script within as root. Full instructions for your operating system are here. Other similar systems such as OpenELEC are available, but I found OpenELEC to be a bit unstable. YMMV, as lots of folks highly recommend OpenELEC.

Then just plug the prepared SD card into your Raspberry Pi and power it up. Simple.

What’s good, what’s bad?


  • XBMC for the Raspberry Pi is pretty much identical to the PC version. It’s slick and easy to use.
  • HD video playback is perfect, right up to 1080p.
  • Navigating menus in XBMC is still pretty smooth, despite the incredibly puny hardware.
  • The system updates itself. All you’ll have to do is reboot occasionally.
  • The XBMC remote app for Android allows you to browse and control all your media files.


  • The RPi likes to fight with my Samsung Smart TV. I don’t know whether it’s the way Samsung have implemented CEC (aka Anynet+) or the way the RPi does, but I found it far easier to just turn off CEC control in my TV’s settings. After that everything worked perfectly.
  • You can’t power off the RPi with the XBMC remote (this is a hardware limitation in ARM). The easiest thing to do is just leave it running constantly, which is mildly wasteful, but only to the tune of about 3W (that’s about 26kWh per year).




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Vent-Axia HR25H Single Room MVHR Review

Posted in Gadgets, Green, Tech on December 1st, 2012 by Andy

I’ve spent a bit of effort draughtproofing my house, which has been great for keeping the place warm. The downside is that a certain level of ventilation is necessary to prevent humidity building up. This means condensation, mould and other nastiness. This winter has been quite bad, with black mould growing on cold spots around the place. That’s unacceptable to me with wee kids in the house, so something needed to be done.

The problem has two solutions:

  1. Get the humidity down by increasing ventilation
  2. Eliminate cold spots where humid air would condense

The main sources of damp in a house will be the bathroom and kitchen. Using a cheap humidity monitor I’ve been tracking our humidity levels and found them consistently above the 70% danger level where problems arise. Clearly we needed to avoid pumping any more moisture into the house, so extract ventilation in the bathroom seems like the top priority.

I’ll be tackling the cold spots in due course too, but for now it’s time for some mechanical ventilation with heat recovery (MVHR).

What is MVHR?

I’m allergic to the idea of simply blowing air we’ve heated with fossil fuels straight out the side of the house, so instead of an extractor fan I went shopping for a through-wall mechanical ventilation heat recovery unit. Unlike a regular extractor fan these also draw in fresh air and pass it over a heat exchanger that recovers some of the heat from the outgoing air. As well as reducing draughts by supplying air to replace that extracted, it will reduce the cooling effect of sucking out the warm moist air.

Is it worth fitting MVHR?

New tightly sealed houses use whole-house MVHR systems, but these are a different kettle of fish. Indeed, fitting one is only worth it if your air tightness is very good. Given that I had a humidity problem I took my air tightness to be somewhat higher than it should be, and coupled to the carbon-saving and comfort boosting properties it seemed the extra expense was worth it.

The Vent-Axia HR25H

I chose the HR25H over several competing products (Envirovent Retrovent and it’s replacement the cringingly-named Heat Sava, Vent-Axia HR25 Solo and Tempra) due to the combination of good performance, low price, and generally positive reviews from owners. The unit is not balanced, it extracts slightly more than it inputs, but this is a plus point in my books as it will draw air from the rest of the house into the bathroom so that other rooms get the benefit too.

Essentially the HR25H is a plastic tube with a divider down the middle. This penetrates the wall, and the fans are mounted on the exterior end, with the filter and electronics on the inner end. A cartridge type plastic heat exchanger sits in the middle of the tube and the whole lot is powered by a switched-mode power supply unit located up to 5m away. Like all MVHR it’s designed to run constantly on trickle and speed up when needed. Like most people I opted for the humidistat controlled version so that it would automatically boost whenever it was needed. Sensitivity is controllable, although getting it right can take a bit of fiddling.


A view inside the existing hole in my wall

Just a smidge of drilling required to make this usable…

To install this MVHR you’ll need a 100mm or 152mm hole through your wall. I already had a large airbrick through the wall, which had been bodged about with during the time of previous owners and currently had a nasty plastic grille. This was a good thing, as core drilling all the way through 300mm of wall is not my idea of fun.

I had hoped to avoid drilling altogether, and simply bash enough of the airbrick out, but the vent narrowed inside the wall too much (difficult to see in the pics). You can hire core drilling kits for around £50, or hire someone else to do it for about £40-90.

It’s important to make sure you drill with a slight downwards slant (which is why the hole isn’t going through the top of the vent in the picture). Sitting a spirit level on the chuck of your drill and tilting until the bubble moves is good enough. This will ensure that any condensation that forms inside the heat exchanger drains outwards. This is important, you will get condensation inside it, and if it can’t escape it will fill up the heat exchanger and the unit will conk out.

The MVHR fitted into the wall and wiring going in

Note the tile-over-tile job from previous owners. I constantly find nasty things like this whenever I do any DIY on this house. Luckily they left some spare tiles for me so I can patch up the hideousness when I’m done.

I fitted a plastic wall sleeve to the hole and filled the rest of the void with expanding foam. I’m sure the latter is awful for the environment, but it’s supremely useful stuff for sealing weird shaped holes and penetrating little gaps. Then it’s simply a matter of sliding the HR25H into the sleeve where it seals very tightly due to the rubber seals around it. The kit includes 5m of cable to run to the power supply unit. I went straight up through the ceiling, across the top of the insulation in the roof and down to the wall outside the bathroom where an existing junction box was close. After wiring the MVHR to the low voltage side of the power supply box and having the mains connected to the high voltage side I hit the switch and it all powered up nicely. The power supply even includes a fuse and a switch, so there’s no requirement for any additional hardware to spur off your existing wiring.


The unit is quiet in trickle mode. You can hear it nearby, but only if you listen for it. After all my hard work I needed a shower and was pleased when boost came on almost immediately.

Boost mode is much noisier, but so is any extractor fan. If I listen up the stairs I can hear it running in the bathroom if the door is open. If you shut the bathroom door it’s barely audible in the bedrooms adjacent to the bathroom, so I won’t be waking anybody up when I’ve got an early start.

Some action snaps:

Time shows 13:27, humidity 70%

Immediately pre-shower. Temperature is reading a little high as I inadvertently left the monitor over a radiator for a few minutes just prior. So much for a controlled experiment…

Time 1332, humidity 87%

Immediately post-shower…

Time 1336, humidity 91%

Peak humidity. The monitor does lag a bit, I assume it’s averaging readings from the last few minutes.

Time 1400, humidity 84%

Seems to be working…

Time 1419, humidity 79%

…yep, definitely working!

Note the drop in temperature. Some of this is due to the accidentally high reading pre-shower, then the effect of running the hot shower, but some drop while ventilating is inevitable. External temperature was pretty chilly, probably no more than 10ºC. No heat exchanger is 100% efficient, and just think how much colder it would have got if we weren’t recovering some of the exhaust heat.

The humidistat is adjustable between 60-90% relative humidity. While the adjustment is just a case of twiddling a knob, you do have to remove the face of the MVHR to do this, which means it’s a screwdriver job. To be honest this is a pain , but once you get it right there should be no need to tinker. I found the best way was to set mine to be relatively insensitive so that it shut off too early. Then I tweaked it downwards until it went into boost again, and kept repeating this until I was happy with the RH level when it shut off.

Power usage is 2W in trickle and 22W in boost. I estimate mine will run in boost for about 2h a day, putting annual consumption at  under 16kWh (assuming it’s switched off for half the year). That’s around £2.25 for me, so worth every penny to prevent nasty mould spores getting at my kids.


Besides a regular clean of the filters little is required. Replacement heat exchangers are available and simple to fit. Some users have reported prematurely dead fans, but they have a five-year warranty on them, so it should only be nuisance value if they do conk out. The electronics are all easily accessible, and you can pull the whole unit out from inside, so there shouldn’t ever be any need to go up a ladder to attend to the outside.


I’m happy with the HR25H. At around £275 delivered it’s substantially cheaper than some of the competition, and performs well. My humidity readings are now in the low 60’s or high 50’s (max has been 67%), and it’s done so without wasting heat. Fitting it was pretty easy, especially since I could use an existing airbrick. Besides an occasional clean out it should do it’s thing without any effort from us, which is just how I like it.

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Ubuntu for Android: could you use your smartphone as a PC?

Posted in Computers, Gadgets, Tech, Ubuntu on March 7th, 2012 by Andy

“In every dual core phone there’s a PC trying to get out”

Or so reckons Canonical, who have been showing off their Ubuntu for Android system at Mobile World Congress. In a nutshell, a phone with Ubuntu for Android turns into a desktop PC when docked to a monitor and keyboard, and a mini media centre when docked to a TV.

It’s a pretty cool idea. There’s already starting to be quite a crossover between phones and tablets, and the latter have been eating into some of the laptop market too. The proliferation of desktop-type Android apps in the market suggest getting access to a full desktop environment when you dock your tablet would be pretty popular. I’m a bit more sceptical that even fast new quad core phones and tablets would be able to produce smooth HD video for a TV, so I think it’s best to take the media centre idea with a pinch of salt. I’ll believe it when I have an Ubuntu for Android machine in my hand and see it working.

You can’t buy a phone with Ubuntu for Android on it yet, you can’t install it like other Android apps and nobody has announced any dates. I think it’s definitely worth keeping an eye out for.  This could well be the next big step in the rise of the smartphone and tablet.

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Review: Pure Sensia internet radio and streaming media player doodad

Posted in Gadgets, Tech on January 16th, 2012 by Andy
The Pure Sensia media player

It's pretty sleek

A new gadget landed in my kitchen over the festive season, an all-signing, all-dancing DAB/FM radio with network media playback and internet streaming functions, disguised as a Martian rugby ball.

Sounds like a mouthful, but it basically takes music or audio from anywhere and boshes it out. Available sources include:

  • FM radio
  • DAB radio
  • UPNP/DLNA media servers on your network
  • Internet radio stations
  • Pure’s “The Lounge” content service

It comes with a touchscreen and a small RF remote. The latter is perfectly good for adjusting volume, but not much else. Actually switching sources and browsing is done on the screen, which is adequate, but often a little sluggish. TBH we’ve got used to better touchscreens in the last few years and this one isn’t quite up to par. Changing volume is particularly fiddly, and I haven’t even got fat fingers. Overall that’s a relatively minor inconvenience, and it’s not so bad you’ll be smashing it in rage.

Setup is very easy, it will find and connect to your wifi easily, and if you’ve already got a UPNP media server sloshing out music across your network connecting to it is straightforward. Likewise “The Lounge”, which provides a web interface you can log in to from any computer and subscribe to podcasts and the like. There’s also full access to all 6 bazillion internet radio stations, and a nice search tool to cut through them to find what you want.

Overall it’s very easy to hook up to a vast amount of content, which is exactly what we wanted for a device like this. But don’t fool yourself, this machine will not replace your main hifi. Sound quality is to be honest a little disappointing. It’s perfectly good enough for some tunes to cook or wash up to, but it has neither the volume nor the quality to do your favourites full justice.

On the plus side power usage is negligible, and the screen has a nice cheerful clock on it when you turn the radio off. There’s the obligatory nod towards “apps” but beyond some basic Twitter/Facebook/Picasa integration there’s not much going on in that department, and who actually wants to stare at their radio reading tweets anyway?

In general this gadget has the right idea, too many internet/radio mashups are missing critical parts of the picture. But the Pure Sensia does include the important bits: FM/DAB radio, internet streaming, network streaming, integrated speakers, and a decent sized touchscreen. Sure, some of those features need a bit of work, and if you want them ironed out your should probably wait for the new Sensia 200 to hit the market, but I’d still recommend the current Sensia as a massive upgrade from your current kitchen tranny.

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How much can a smart thermostat really save?

Posted in Gadgets, Green, Tech on October 30th, 2011 by Andy
A stuffed polar bear wearing a scarf

Keep warm and save polar bears this winter

Here comes winter again, time to crank up that central heating. But if you’re using an old-fashioned manual thermostat, you could be burning a lot of money for no good reason.

A programmable thermostat differs from a regular thermostat in that you can set it to provide different levels of heat at different times or on different days. They’re generally a straight swap for your old one, and cost about £50. Fitting it should just be a matter of unscrewing the old one from the wall, and switching the two wires that control your boiler to the new device.

Having fitted one of these beasties, you now have full control over exactly how warm you want the house and when. That means you can have it automatically warm up in time for getting out of bed or home from work, and cool down to save money (and polar bears) when you’re not in or asleep.

Will it save money and/or the planet?

Yes, if you tell it to.

For example, having it automatically lower the temperature by 5º overnight when you’re safely tucked up in your duvet can save you about £15 over the course of the winter. Which doesn’t sound like a lot, but it’s money for nothing, and it would save about 70kg of CO2 emissions (or about 200kg if you use grid electricity for heating). It’s also a lot cheaper than fitting a more efficient boiler.

A programmable thermostatIf you’re at work Mon-Fri you could save even more. Setting it to frost protection only for 7 hours a day could save you £80 and 335kg of CO2 over the winter compared to leaving the heating at 18º. And that still leaves plenty of time for it to warm back up before you get home.

So you can see that even if you’re heating your home really comfortably, using a smart thermostat to avoid heating it when you don’t have to can pay for itself easily. Sure, you could achieve some of the same savings by manually turning your stat up and down, but having it done automatically is much easier.

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How to upgrade the wifi on your Eee PC

Posted in Computers, Gadgets, Howto, Tech on September 4th, 2011 by Andy
Two giant clusters of antennas poking above some trees

Here's one I upgraded earlier

Wifi comes in different speeds. The latest and fastest is 802.11n, or wifi-n. It’s pretty quick, but what if your Eee PC is an older model that only has wifi-g? Upgrading is actually really easy, and besides more speed should give you better range.

You’ll need a new wifi-n mini-PCI Express card, I used an Intel 4695 AGN because Intel are really widely supported. You can pick them up for tuppence on Ebay. You’ll also need a third antenna, which you can get here.

  • Remove the battery and pop the bottom cover off your machine
  • Disconnect the antennas, remove the two screws and remove the old wifi card.
  • Route your new third antenna along the front edge of the inside of the case. The orientation of the antenna is important, and luckily there’s plenty of room for it if you run it under the RAM stick.
  • Fit the new card and attach the antennas (the new one goes on post #3)
  • Power up and enjoy.

I’m running Ubuntu, so it all worked as soon as I switched on. If you’re on Windows you might need to download some drivers from Intel and do the little Windows next > next > next > reboot dance. If you do have any problems booting try clearing the CMOS (remove the battery, remove the RAM and short out the two copper patches underneath it).

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How to get your Sky broadband username and password

Posted in Computers, Gadgets, Howto, Tech on February 11th, 2011 by Andy
A padlocked door

Just say no to pointlessly locked technology

Sky broadband is a pretty attractive package if you already subscribe to their TV, but it does have one annoying snag. Sky insist that you connect using the router they provide, and enforce this by locking the box down with custom firmware that obscures your actual username and password. This means you can’t connect using any of your own hardware.

While this might sound great if you’re a Sky first line support monkey, it’s a pain for the customer.

Sky have used several different boxes over the years, and cracks for all of them have been published, which is a good enough reason to think twice about using the hardware they supply.

Get the tools:

If you have a Netgear or Sagem router:

If you have the new D-Link router:

Note that although the T&Cs say that the router Sky sends you does become your property, you should keep hold of it, as Sky are unlikely to provide tech support to you otherwise.

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The Top 5 Android apps for people with new babies

Posted in Gadgets, Tech on August 4th, 2010 by Andy

A babygrow with the Android logo printed on itHaving a baby is a pretty major change in your life, and things tend to get a bit hectic. I’ve found having a device in my pocket that can help smooth the way a bit really helps.

    Just Noise

    This app is like having a magic button on your phone that soothes grumpy babies. For some reason babies find white noise really relaxing. I’ve used this one to get my daughter off to sleep many, many times.

    Remember the Milk

    All of a sudden your life has just got a lot more complicated. Unfortunately this also coincides with a new adventure in sleep deprivation. Having an app that can organise you life and remind you to do things is invaluable. You can set recurring tasks, organise them by lists, tags, and a heap of other features. Requires a Remember the Milk Pro account, but the US$25 a year is well spent.


    If you’re going to spend countless hours sitting up awake at night settling babies, you might as well do something useful with your time. Aldiko is a great ebook reader that actually makes reading on a small screen quite enjoyable. Plus it has a huge supply of free books ready to download. Mostly that means old book that are out of copyright, but if you can handle reading the Sherlock Holmes novels, War of the Worlds or some Sun Tzu then you’ll be fine.

    One handed reading is a very useful thing to be able to do when you’ve got a bundle in the other arm. Another good option if you’ve got a Kindle is their Android app. It will even remember what page you were on when you switch back to the Kindle

    Quick Alarm

    Simple app, but does the job. Set yourself an alarm for a 20min catnap when you get the chance, and fight back against the sleep deprivation.

    Baby ESP

    Plotting and recording when your child eats, sleeps and poops may sound a bit anal, but it can also make your life a lot easier. Sometimes you don’t realise your baby has fallen into a routine until you track it, and then knowing when they’re going to do what ahead of time is a huge win. This is a paid app, but you get a fully functional seven day trial. And it’s only US$3 anyway.

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