The non-geek's guide to fixing troublesome gadgets

Make the right connection

If watching films on your new DVD player is disappointing, make sure that you've got the right connector lead running from your machine into the TV. If you've bought a fairly basic (£30 or so) DVD player, then by all means use a cheap Scart lead - you can get them for around £10, and they're fine. But if you've gone for an HD DVD or a Blu-ray player - for the new generation of HD TV - you should budget for a more expensive cable. A Blu-ray player can cost £1,295, so don't skimp on the quality of the connector - allow another £50-£100. For HD DVD or Blu-ray, you need to use an HDMI (High-Definition Multimedia Interface) lead, not a Scart. Otherwise, the extra picture quality will be lost. HD television will always look best if you're watching a programme that has been filmed, edited and recorded - or broadcast - in HD. Other films can be boosted by the HD DVD or Blu-ray player, and they'll look a little better than normal DVDs, but if your HD TV hasn't really wowed you, try watching a new film that has been made specifically for HD.

Dial 'A' for accidental

Forgetting to switch on the keyguard is one of the most common - and costly - mistakes made by those new to mobile phones. It also happens when people switch to a new brand, and have to get into the habit of pressing different buttons to lock the keypad, and thus stop themselves dialling numbers or sending texts by accident.

There is a simple safeguard that can prevent many such accidental calls. In your address book, save a number that will not work (eg 1111), and give it the name "A". It will appear at the top of your address book, which, when a phone is loose in a bag or pocket, is often the number incorrectly called. This way, accidental calls won't connect, you won't be charged, and your friends will be spared the 15 minute-long answerphone messages you may otherwise leave in error.

A frosty reception

Does your new digital radio cut out? Although DAB should never crackle or hiss, people who think that coverage is guaranteed to be perfect everywhere are sometimes disappointed. Before you buy, go to www.bbc.co.uk/digitalradio/listen/postcode.shtml, and, when you have put in your postcode, it will check the coverage in your area. That way, you can be confident that you won't experience signal "drop-out".

The bigger picture

Many people will have decided that, some time before the next Queen's speech, they want to replace their existing set with a new high-definition television (HD-TV). But think before you part with your money. On a big screen, an HD picture will look incredible - we have a 50in screen in the store, linked to a Blu-ray player, and the picture quality is breathtaking. But on smaller sets, you won't notice the difference as much. You can get HD televisions with screens from around 20in, but I'd say that you only really start to see the benefits if the screen measures at least 32in. If you're looking for a smaller set, it may not be worth spending any extra on HD.

You are surrounded

If you're putting together a home-cinema package, don't neglect to position your speakers properly - some people go to the effort of hanging their new plasma screen on the wall, but then fail to put the speakers in the right position because they can't be bothered to lift the carpet to hide the wires. You only get the best out of surround sound if the speakers are in the right place. The more expensive systems come with a microphone, which indicate whether you have the speakers in the right position, but even the cheaper systems will work very well if you follow the room plan in the instructions. The best systems are called "5.1", and have five small speakers plus a bass speaker. If you can't face hiding so many cables, you can go for a "2.1" system, with just two speakers, plus the bass box.

Aerial view

If you've recently bought a television for, say, a kitchen or a bedroom, you may be having trouble getting good reception. Small indoor aerials don't always work perfectly - it depends largely on where you live, but we're all used to the hassle of adjusting the position of an aerial to get watchable picture quality, and even then, some people struggle to pick up certain channels. Of course, you could add an aerial socket from the main aerial, but this is often far from simple. Another option is to buy a video sender. This consists of two small boxes - one sits next to your main television, the other near your second set, and the programmes are beamed wirelessly between the two. They work with Freeview, Sky, cable television and DVD players.

Snap happy

In the past couple of years, digital cameras have come a long way. Many compact cameras now offer six megapixels or more, which gives amazing quality. They're all the camera you'll ever need (you can even get decent A3 prints). But this also means that memory cards can fill up quickly due to increased file sizes. Buying large-capacity memory cards can be expensive, so it's worth remembering that you only need a three-megapixel image to produce a top-quality 6x4in print. This means that you don't have to have your camera on the highest-quality setting. Reduce it and you'll fit more pictures on your memory card. Another common complaint is that, with some digital cameras, there's a delay between the button being pressed and the photo taken. To get around this, hold the shutter-release button halfway down, so the camera can work out focus and exposure settings, then, when you're ready, squeeze the button down further. You should see the delay greatly reduced.

Now hear this...

You can always make an MP3 player sound better by upgrading from the free headphones - the ones that come in the box are really just there to get you started. The difference it can make is amazing, and even a cheap MP3 player will sound much better through decent headphones. We're not talking big money - £30 will buy you a decent pair of headphones by Sony, though a Bose pair for £70 will sound better still. The other thing to do, if you're disappointed with the sound, is to check the MP3 files themselves. You can usually choose to vary the quality of the files, measured in kilobits per second (kbps). The higher the number, the better the quality - opt for 128kbps and you'll get near-CD quality.

Put it in the family album

Most people who want a photo printer are very happy with a simple, small machine that does 6x4in prints. However, for whichever one you choose, there is a golden rule: ensure that you buy the photo paper and ink cartridges from the same manufacturer as the printer itself. Getting the exact amount of ink and colour balance is a complicated process, and if you put, say, Epson paper into a Canon printer, the results may not be that great. It doesn't matter which make of camera you use.

A series of Tech Tutorials is running this month at John Lewis, Oxford Street, London W1. For more information and to book an appointment, call 020-7629 7711 and ask for extension 5001