Category: Electronics

Sony Discman D-121 Pt:2

Assessment and fault finding… will it work?

My recent purchase of a Sony Discman D-121 from EBay has arrived. Just as described it wasn’t really working so I decided to give it a once over to check condition.

Cosmetically sound

Cosmetically it’s in very good condition, open the battery compartment and it’s a different story, definite signs of corrosion and at this point I’m thinking the worst. I put two batteries in to check, the display comes on and shows some strange indication of “HI VOLTS” even though all I have are the two AA batteries in. Strange.

Corrosion on contact
On the board as well

I do manage to play one song but that’s it, any slight move and it skips and hops and shows a raft of other error messages that don’t Instil any confidence into me that this is going to have a good outcome. Then the CD drive motor breathes its last. That’s it….kaput.

Greasing the worm gear
Strip down

So I open up the unit, and put the circuit board under the microscope. The area around the corroded battery terminal has progressed on to the board and a couple of the circuit board tracks have been totally destroyed. A few components look to have issues and have some spurious test results. A check for continuity with the multimeter confirms that one track is dead and another is intermittent at the very least.

Under the microscope

I clean the offending section of the circuit board with IPA and this just confirms the issue, but at least it looks cleaner. If this had been the only issue I’d have happily soldered in a couple of thin wires to the undamaged track to ensure a reliable continuity.

Damaged tracks
Bad corrosion

A further look around the board, and there’s nothing blatantly obvious, but seeing this unit was produced in 1993 it’s now in its 31st year of use I also suspect the capacitors (of which there are many) may well be of that era of suspect capacitors I discussed on a previous post. Read here: Capacitor plague

The main drive motor is known to fail after time and a sure sign is if the CD jumps when moved off the horizontal, apparently this is due to bearings becoming misshapen due to use.

This unit therefore is beyond economical repair for me, and I’m not going to progress it any further. The good news is that I can use the unit for spares and as a number of these older units have interchangeable parts, I’m hopeful that as I have a few more units turning up later this week they may have a willing donor.

So the recycling goes on, and that’s always a good thing.

Happy day to you all.

Bardic Lamp…A railway classic

The Bardic lamp was introduced into the British railway system by the Bardic company of Southampton sometime around 1962. Just about everyone who has worked on the railway since then in a trackside role was given one as a personal issue.

Fast forward to today and new plastic LED lamps are being issued, however they don’t have the appeal of the old lamps, they break easy and the lens colours are not true Red, Green and Amber that they should be. The old style Bardic lamp is still in use many of which are still being used today. I still have the original one issued to me back in 1992.

This post is going to cover a basic power conversion for these lamps that will hopefully result in them being used for many more years.

Bardic lamp
Ever ready AD28 battery
Two that I have recently converted at work

The fundamental issue with these lamps is that they use an old Mercury cadmium battery that accepts two pins that insert into the top of the cell. Even though these batteries used to be available for a reasonable amount of money, nowadays it is unethical to purchase these batteries due to their construction they have in theory been banned, so they are no longer manufactured. They can though still be purchased via the web at extremely inflated prices, however they can’t guarantee that they would still work – so you take your chances.

With this simple conversion we can extend the life of this unit and save it from being cast aside as waste. The conversion is very cheap, uses std “D” cell batteries and can be converted by anyone – even me. Kits to do this can be purchased for around £10 (GBP) on line, but this one should not cost more than £2 (GBP) even less if you have the parts as spares.

There are two ways of doing this conversion, the way the kit works is to use a couple of electrical “Choc bloc” adaptors to connect to the male pins of the AD28 connector (I’ve used that example on this page). The cheaper option is simply to have a 3 cell “D” type battery holder, cut the old AD28 connector off, solder the two wires together and use some heat shrink to cover the solder joints. Simple.

This really is a ten minute job that increases the lifespan by years.

Bardic lamp old AD28 connector
Bardic lamp conversion

The conversion is completed with the D cell battery holder being stuck to the base with some hot glue. I’ve also put some on the chocolate bloc connectors for some extra strength and protection from the damp.

We recycle these batteries at work with a company that we have connections with, I also take spent batteries to the local supermarket that also recycles. The old AD28 batteries go to a specialist company for recycling/disposal.

Pretty basic and I now have a constant supply of these coming into us from our locations throughout the East Midlands awaiting conversion. We now do the basic simple conversion with our own stock and I think we have the conversion cost down to about £1.80 GBP per unit. A very cost effective simple conversion that will keep a 50+ year old lamp going for a few more years.

Sony Discman D-121

Anyone remember these? To say they were popular in my younger years is an understatement. Originally I had the Walkman (A cassette tape version) and I came to the Compact disc quite late in the 1990’s to be honest. Lately I’ve been looking at getting a Discman as I do still have an amount of discs at home and I like to listen to my old music whilst walking the dog. Yep I have my phone and Spotify so I guess I have access to pretty much everything there is out there but I just fancy trying a bit of retro and stepping back into my formative years.

Why not buy one that needs attention? I can kill two birds with one stone, get a repair on this site hopefully and the jobs a good one.

So off to EBay I trot and find this Sony Discman D121 that the seller agrees to sell to me for my offer of £10 GBP.

Sony Discman D121
Sony Discman D121

I expect age related issues, as this particular model was produced sometime in the mid to late 90s. This one has an issue where the disc isn’t recognised and is intermittent. This range has a few known issues and to be honest I don’t think I will have too much trouble in getting this one going again (Famous last words 🤦‍♂️)

I’m expecting its arrival sometime in the coming week so I’ll come back to this post when it’s in my possession for an update on its condition.

Update: 9/3/24 23:11 – For some reason I’ve now purchased a damaged Discman D171 as well🤦‍♂️ I’m a glutton for punishment.

Sony Discman D171

Further update: 11/3/24 22:30 – Stop 🛑 🛑 just 🛑 😳

For some reason I’ve just brought another 2 faulty Discman. This time the D-141, two of them. That’s it I’ve got to stop now 😂 really I have to stop 🛑

Sony Discman D-141 x2

Thanks for passing by. Always appreciated.

Capacitor plague

What the heck is that?

Blown capacitors

Photo copyright : Wikimedia Commons

For many this is old news and pretty much everyone involved in electronics is aware of this problem that swept through the industry in the mid to late 2000s. Chances are you may have such a unit in your home that has either luckily survived the issue to still be working, or may well be not working and assigned to that part of the house (Normally the loft) where it left until the day you move premises and visit the local tip.

Those of us that number a great many who like to tinker and repair old machines and equipment from this era are still seeing the back end of this issue to this day, its fairly easy to deal with and those that especially work with old computer motherboards and graphics card notice issues the most, its an interesting back story and ill try to cover it as best as i can in this post.

What is a capacitor?

  • A capacitor is a device that stores electrical energy by accumulating electrical charges on two closely spaced surfaces that are insulated from each other. It is like a little battery but thats where the similarities end, as a capacitor distributes energy in short bursts rather than a battery that is distributing power linearly. Originally known as the condenser, the capacitor is used within a circuit to add capacitance to that circuit.
  • Capacitance is the ability of a component to store an electrical charge – (Simple version)

What was the issue?

  • The issue was with Electrolytic capacitors produced between 1999 and 2007
  • The origins of the issue was with the use of water based electrolytes developed during the late 90s. These capacitors using this type of electrolyte were found to be exceptional components when used in power supply circuits. The problem was that the water based caps produced aluminium oxide when reacting with the capacitor “Can” and that reaction was Hydrogen. The Hydrogen built up until the stamped vent on the top broke. Resulting in a failure within the circuit.

It was only in the mid 2000s when the plague really set in, some of these capacitors would have had hundreds of thousands of hours of use and even though they would have passed initial testing protocols they were doomed to fail, and that just so happened to be in the mid 2000s.

The Blame game

It was around this time with exceptional failure rates on certain items and claims being raised against major players in the electronics industry that deeper investigation took place.

Findings

  • The cause of the failures was due to a mis-copied formula, in 2001 a scientist working for a major corporation that made these type of capacitors stole a mis-copied formula for the capacitors electrolytes. He then took this faulty formula to another company. That same year the scientists staff where he previously was employed left that company, again with the stolen formula and started their own company in Taiwan producing immense amounts of faulty capacitor electrolytes.
  • No one was ever really brought to justice for the failures, no one company ever really came clean over the issue, the tech companies tended to absorb the cost of repairs and the end result was probably that the consumer paid in the long run…nothing changes there then!

When this started to occur, many individuals in the industry jumped on the band wagon to repair these items, many selling capacitor kits for certain brands to allow those who were willing, to make their own repairs.

Today the issue still occurs but it is not so prevalent, older circuitry does still throw up some classic blown capacitors and these are fairly simple to replace, some smell quite fishy as well, so sometimes a good sniff of a circuit board can alert you to a blown capacitor…very strange!

Roberts Blutune T2 breakdown and fault finding

The radio has been received see here: Not just Dead….Fully dead and if I can’t get it going, I have at least brought a very tidy storage box.

What surprised me when first opening up this radio was the immense amount of boards and circuitry inside, I must admit I took a gulp at this and questioned my reasoning for purchasing the item. However it’s all a learning curve and I have to start somewhere, gone are the days of simple circuits on traditional radios (with big components).

Roberts blutune circuitry
Roberts blutune power board
Roberts blutune circuitry

I arrived home from work and sat myself down in the conservatory surrounded by test devices for about 4 hrs until I totally overloaded my self with information, creating more questions than answers, i decided to give up for the day and further research the potential faults for this unit via other sources.

To me the power board seems fine, power is going where it should, there appears to be no short circuits or component damage however in places there does seem to be some signs of leakage so I may have some components that need replacing or maybe it’s just remnants of flux and stuff left behind after initial construction.

Blutune board under microscope
Blutune board under microscope

None of this can be seen by the naked eye but it becomes apparent after being placed under my new toy an Andonstar microscope viewer. It’s at the entry end of the range but it is already becoming a game changer for me, due to my failing eyesight.

Andonstar AD106S

Copyright Andonstar

Further investigation appears to highlight an inherent issue with this range of radios when they just seem to stop working (probably why Roberts ceased production).

Generally the power board isn’t an issue, it all focuses around the display board where a controller to the screen has failed or the amplifier chip has failed, hooray I say! And then I find out both components are about the size of a grain of rice… Boo I say.

I have no experience at all in components this minuscule in size, but if I can’t get to the root cause and eliminate all other possibilities I will give it a go. In the meantime fault finding will go on between other jobs and this will continue to be a job in progress that will be revisited and updated as time goes by.

The plan short term is that I’m going to borrow a thermal camera and check if there are any hotspots under electrical load. You never know I might just find something.

I shall comeback to this project at a later date.

Thanks for passing by. Stay safe, be superb. You’re a star 🌟

Not just Dead….Fully dead

I have just brought this inoperative Roberts Dab Blutune T2 digital radio off of EBay for £8 (GBP). I managed to barter the price down a bit from £12 and I was quite pleased with myself for doing that.

Roberts Blutune T2
Roberts Blutune T2

So today I have received the package. A lovely little item cosmetically in good condition with the only external damage being that the speaker cover has a tiny tear in it , and the very tip of the aerial is broken along with the plastic stop that secures it when in the down position….no real issue, all easily dealt with.

The concern is the label on the top of the unit. Fully Dead!

Roberts Blutune T2

So what’s that then? Is there an in between? Some sort of purgatory for audio systems, or is it a way of saying that someone has ensured it will never work again?

Well, I’ll get the back off tomorrow and have a rummage to see what’s in store for me. Maybe my bartering of the price has meant the seller has removed all internal contents so that I now have a nice “Empty box”.

I just love some of these descriptions sellers use, makes me giggle and wonder what was going through their minds when they decided to sell an item that is fully dead.

Maybe there is just different grades of death that I was just not aware of.

You can find the assessment and repair attempt here: Roberts Blutune T2 breakdown and fault finding

Anyway, thanks for passing by, be safe, be happy.

First steps

So most of my adult life I have convinced myself that despite having a hatful of interests there was nothing that I was particularly any good at. It’s strange really how you always knock yourself back if you don’t have that much confidence. In truth it really is quite the opposite. I started out in Photography way back in the days before digital when you had to get your hands wet to produce results, for me the old Silver halide era of photography cannot be matched or equalled and personally I think anyone can be a photographer these days, however give them developing tanks, print dryers developers and fixers an enlarger and then ask them to dodge and burn prints and then retouch them and the result might be slightly different. I remember days when I used to photograph weddings and shoot maybe 6-8 rolls of film, a friend of mine in the digital arena shoots maybe 2-3000 exposures per outing! Wow, she will never experience the fear of having a blank film post processing.

On top of this I’ve had an interest in electronics from an early age, I used to visit jumble sales as a kid, buy old radios and repair them and sell them on to get some pocket money. I obtained a city and guilds in electronics back in 2000 as well as an “A” class Radio Amateur qualification (M0ESB) so yes I’m a Radio amateur as well. I could have ventured into a job role utilising this however I preferred to maintain it as a hobby as I didn’t want to fall out of love with electronics.

I also enjoy arty stuff, I love painting both pictures and stuff, tarting stuff up – you know what I mean. I have recently had lessons in the Bob Ross method of painting with a local tutor and I really enjoy this. I’ve always enjoyed making models and painting them and I like building small dioramas as well so I can be quite crafty when I put my mind to it.

So to return to the start when I was searching for my worth as such, I have decided to combine a number of these hobby/experiences and I will be purchasing old unloved equipment, making it good “Tarting it up” and hopefully moving it on either for decorative purposes, for use as props or even returning it to its original purpose.

The site is new and I’ve kind of jumped the gun by getting this up and running before I have any projects on the go or even stock to use in those projects. Hey ho, that’s the way I roll is anyone else as ass about face at doing things as I am?

Hopefully I can record my progress through this site that is a new venture for me as of Feb 2023.

Maybe you as a visitor will follow my journey, maybe you will pass on through, however please feel free to feedback any constructive advice as we can all learn from that.