Wired for sound: AKG Headphones repaired

A pair of decent studio headphones dodges the bin…

Headphones are big business and global sales of these devices reach over $500m per year in the U.S. alone (quick Google search, so it must be right eh). As I’m sure you do; When I read sales figures like that, I wonder what the average life expectancy of headphones is, as I’m sure that many sets are viewed as disposable items.

Bluetooth and other wireless headphones aside, most wired headphones are fairly straightforward to mend, assuming no damage has been done to the speaker or ‘phones’ part. You just need basic tools, some patience and a fair bit of nerve… See how I got on with this pair of AKG K92s.

Make and model: AKG Headphones K92

Fault reported: No left channel

Cost of replacement: £35 when new

Manufacturer support:  0/10

Cost of parts: £0.00

My repair time: 45 mins

Tools needed: Soldering iron, small screwdrivers

Sundry items: Insulation tape, holt melt glue

Cleaning materials: N/A

Repair difficulty: 4/10

Cups of tea: 1

Biscuits: No biscuits this time, as it was lunchtime. It was cheese on toast for me, with some chorizo on top as I seem to remember, maybe a dash, just a tad, of tomato sauce- from Lidl I think…

I’d just finished the last mouthful of tea, I was getting peckish, thinking about putting the grill on, when a neighbour of mine rang the doorbell, at lunchtime -of all times.

The conversation went like this; Matt, could you have look at these old headphones for me? I was about to chuck them out and I know you like playing with old stuff like this. They used to be good, but they only work ‘one side’ now. I mean, they’ve probably had it. …Hang on I said, let me have a look, leave it with me. Famous last words.

I was quite flattered actually, as I really do like receiving work this way. When there’s little hope for something that’s probably on its way to the great scrap bin in the sky, I must admit that I especially like taking on that challenge of making something work again. Diverting the once condemned item back into full service is the thing that keeps me motivated.

On with the repair. The fault reported was ‘no sound from the left speaker’. The first thing to check with anything corded is the cord/ flex/ wire itself. While a visual check of a wire is no conclusive way of proving that it works or not, tell-tale signs of bending and chaffing can save a lot of time elsewhere. Rule out anything silly before wielding screwdrivers, I say.

Since the wire looked OK and the plug wasn’t bent, it was time to take the headphones apart. The AKG K92 headphones are simple to dismantle; just pull-off the headphone covers and the speakers are held together with just four small cross head screws, each side.

Using a multimeter set to continuity test, I was able to prove each part of the cable. The main wire from plug to headphone set proved OK, which was a good thing as it meant no replacement required (these are widely available on eBay). The headphones’ over the head band, as well as keeping things snug on ones’ noggin, also carries the signal from one side of the set to the other. If you’re still reading, I hope that makes sense. Anyway, the meter proved that it was all fine.

FixItWorkshop, Worthing, AKG K92 headphones, left channel re-wiring.

In the end, the fault lay with the main wire to headphone speaker on the left side. To be honest, I should have checked that first as that connection is always under load as it crosses a pivot point, allowing a few degrees of movement and therefore comfort for the user.

On the subject of comfort, while doing the repair, I noticed that the headband was a little torn at each end, presumably a result from many intense sonic moments. The vinyl coated band was a tricky customer to repair, but a little hot melt glue along the torn edges, soon fixed things, giving the headphones a fresh feel.

A quick remake of the connection (cut cable, re-solder) and full hi-fi was restored and the headphones were ready to blast again. Turn it up to 11.

Jonathan Deer the III

A Christmas novelty toy gets a new lease of life…

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FixItWorkshop, Worthing, December 2019, Jonathan Deer III.

I meet some really interesting people with this hobby of mine with some quirky things to fix, often with personal and meaningful backstories.  This repair is one such item.

Make and model: Jonathan Deer III rubber deer thingy

Fault reported: Not running

Cost of replacement: About £0

Cost of parts: £0.00

Hours spent on repair: 2

Tools needed: Cutters, screwdriver and soldering iron

Sundry items: Contact cleaner

Repair difficulty: 2/10

Cups of tea: 2

Biscuits: 0

Someone got in touch to see if I could repair a festive family favourite Christmas novelty, which was a big hit with the children, back in the day.  Jonathan Deer III has become a family legend and Christmas simply wouldn’t be complete without him.  Intrigued, I agreed to see the injured deer.

A few days later, a parcel arrived and upon opening, I was greeted with a deer’s head made of rubber.  Not one’s average delivery.

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‘Jonathan Deer’ was available about 20 years ago in the UK and I suspect the US as a novelty singing Christmas toy, designed to hang on the wall, to bring festive joy when anyone walks past the deer’s motion sensor.

Sadly, or maybe fortuitously, depending on your perspective, Jonathan was now silent and despite new batteries, it was dead.

The thing about Christmas decorations is that they get used for about 4 weeks a year and then packed away, usually in a loft or alike where it’s not necessarily that warm or dry for the remaining 48 weeks.  Cold, damp and draughty conditions are not good for small electrical items.  Batteries left leak and metallic contacts corrode and these ailments had affected poor old Jonathan.

Repairs completed:

  • Battery terminals were corroded from battery leakage and therefore cleaned with a small toothbrush and protected with contact cleaner
  • Opening up the casing (several small screws) revealed a broken negative lead.  A Small re-soldering job fixed that

Still no action.

  • Lastly, the on/off switch didn’t seem to be working.  I was able to separate the small tangs holding the switch together and gently clean the switch wiper/ contacts with cleaning agent.  I didn’t replace the switch as it’s a bespoke item and getting a replacement would be difficult.  The repair I made seemed to work OK.

Once the switch was cleaned, Jonathan burst into life.  Upon switching him on in demo mode, he woke up by blaring out James Brown – I Feel Good.  Moving the switch to on mode, he worked as he should via the motion sensor.  Wonderful.

I was then able to return the deer to its owner to enjoy over the festive season.  Result.

A broken massage belt, with a happy ending…

An Invitalis Massage Belt gets a simple repair at the workshop.

I was asked to repair a personal massage belt recently, which had developed an annoying habit of cutting out, mid-treatment.  Over email, I confessed that I did not know what a massage belt was, but was reassured that is was used to treat lower back ailments and nothing more personal.  Phew.

Make and model:  Invitalis Vitalymed Flexi massage belt

Fault reported: Cutting out

Cost of replacement:  About £40.00

Cost of parts:  £1.29

Hours spent on repair:  1

Tools needed:  Small flat-bladed screwdriver, soldering iron

Sundry items: None

Repair difficulty:  2/10

Cups of tea:  1

Biscuits:  1 Goldbar

 

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FixItWorkshop, Worthing, August’19, Invitalis Vitalymed Flexi massage belt.

These devices are sold on Amazon and are usually available at events, such as the Ideal Home Exhibition and alike.  This belt offers the wearer a lower back massage by means of two rotating arms with smooth spheres, hidden behind a soft pad.  The spheres also emit infra-red, if required.

I don’t know much about this kind of thing, but I had noticed that the power cable for the belt was a standard female 12VDC connector, used on many types of domestic equipment.

With the power applied and with some wiggling, the belt would occasionally come on and then fail, indicating a loose connection.  The trick here was to find out where.

The belt is zipped together and access to the wiring was easy.  The belt’s power connector ran to a switch/mode box and then on to the motors and other gizmos within (see photos in slideshow).

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After cutting into the cable, testing continuity, I found two problems; A break within one of the cable cores and a faulty female power connector.  Luckily, connectors like this are abundant and a quick look on eBay revealed lots for under £2, delivered.  As it happens, I bought a high-quality connector and flying lead, intended for a CCTV camera, to fit the belt.

The last step was to reconnect some good cable, reconnect the new connector and make good with soldered joints and heat shrink, to keep everything nice and tidy.  Before I solder things, I always make sure I’ve not cross-wired anything, by proving continuity with a multimeter.  In the past, one has been known to blow things up by not taking this sensible approach!

After reassembly, it was just a case of powering up and switching on.  Gladly, I hadn’t crossed any cables and it now worked again, happily ever after.

Aldi Bauhn Radio with no power

A cheap radio gets a cheap fix.

I love a good radio.  I used to collect them as a kid, working or not, do them up, get them working and I eventually ended up with, er… lots.  I’ve since scaled my collection back a bit these days to around 10 or so, quite frankly more than is healthy really.

So when someone got in touch recently with a broken DAB radio to fix, I got quite excited.

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FixItWorkshop, Worthing, February’19, Bauhn DAB Radio.

These Bauhn DAB radios (available from Aldi or Lidl in the UK, I think) were on the market for about £10 and at that price they represent great value when compared to more expensive devices.

However, the one in the workshop appeared to have a problem power connector, which when wobbled, made the radio work intermittently.  Suspicious.

Having already repaired a similar radio with a similar fault before, I decided to video the repair to encourage others to check theirs, if something similar happens.  I hope you find it useful.

 

Happy fixing!

Cost of a new radio:  £10.  Cost of repair:  One cuppa and a bit of tinker time.

Lucky Voice Microphone without the X-Factor

Lucky Voice Microphone repaired.

A colleague of mine came in with a broken microphone, which is part of a Lucky Voice karaoke set and retails for about £60.00 on Amazon.  The microphone had worked pretty well, but recently had lost its ‘X-Factor’ somewhat.

The microphone is fairly standard fare and connects to a standard XLR plug and socket arrangement.  As this part is usually under the most stress as the singer moves about, it seemed sensible to have a look at that first.  Upon connection to my amp, there was a huge amount of crackling which seemed to coincide with cable movements at the microphone end.  Swapping the lead for a known good one I had proved that the microphone was fine, but the lead not so fine.

Only one screw holds the plug together and straightaway, the problem presented itself.

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FixItWorkshop, Oct’17, X-Factor microphone, XLR connector.

The main core had detached from the connector, as the outer cable sheathing has come away from the XLR connector body clamp.  Not ideal.

A quick strip back and solder job and the wires were connected back where they needed to be.  A little dab of hot-melt glue on the cable grip and a re-tighten and the cable was not going to move anyway.

With the plug re-assembled and the screw put back, the microphone tested perfectly on the amp, ready for karaoke once more.

Cost of a new similar lead: £10,  Cost of repair: 15 minutes, dab of glue and solder.  Nice.

Testing, testing, 1-2-what?

My Fairlady sings again…

When my wife isn’t looking after our daughter, she sings part-time in and around Sussex and uses a simple portable microphone and amplifier set for gigs. The amp and the rest of the kit lead a hard life, being transported between the car boot and venue and on one occasion, the microphone was dropped from a height.  I guess things could have been worse, it could have been the amp!

The microphone now rattled badly and seemed to cut out when connected up, even when turned up to 11.  Not a good sound when she was in the middle of ‘Moon River’.

The microphone actually came from a Lidl karaoke set and is made by Silvercrest, a Lidl brand.  It’s a heavy, metal bodied microphone with a decent quality feel and metal grilled top.

The rattle seemed to coincide with the cutting out, so it seemed sensible to open up the mic.  Three Phillips screws hold the casing together and upon opening it up, the problem quickly became apparent.  The metal weight inside had come away from the inside of the casing and was occasionally ‘shorting’ the connections on the back of the on/off switch.  Not good.

While in bits, I checked all the wiring for continuity, no problems there and decided to clean the switch with contact cleaner for good measure.  Once all the electrical side of the mic was proved, I reassembled the casing with the parts, adding a little hot-melt glue to the metal weight to prevent it coming in to contact with the back of the on/off switch.

This wasn’t the end of the song (sorry).

Upon hooking the mic up to the amp, it now worked again without cutting out, but I couldn’t help but notice that the lead connecting to the base of the mic seemed to be causing a slight crackle.  Not a nice sound effect.

Opening up the three-pin mic connector revealed a simple design, three poles soldered to the microphone’s wiring, one core and one screen.  A quick cut, strip and re-solder and the lead was ready to roll once again.  Before I did the cable crimp back up, I added another dab of hot melt glue between the cable outer and flex guard, to ensure the cable couldn’t twist, which might cause the connector to fail again.

Cost of a new microphone £20+.  Cost of repair; Time plus soldering and a bit of glue.

‘My Fairlady’ sings again…