Electronics – Page 8

Sony Discman D-171

Assessment and fault finding….will it work ?

My latest purchase from EBay has arrived and god knows what is wrong with this one as the listing contained just one word “Untested”.

There is no one else to blame but me so let’s get this package open and have a look…here goes.

This unit is circa 1996, so there is a gap of 3 years between this and the D-121 that i recently attempted repair on that was badly affected by poor components. Hopefully technology has moved on slightly in those three years, and the plague of the past isn’t as prevalent in this unit.

Well, once in your life you buy something that restores your faith in your fellow man, unfortunately EBay isn’t always that place and you have to take your chances when purchasing using that platform. Today is a good day. The package was minimal and I didn’t hold out much hope. The first thing I did was to open the tray, good it’s working👍

Next I held my breath and opened the battery compartment…. Excellent no corrosion 👍

Batteries inserted I chose an old Bryan Adams album, put the volume about mid way and turned it on.

IT WORKED 😳

Ok, if tapped it jumps, so I will give the lens a clean and will lubricate the worm gear and rail and see if that helps, if not I might test the laser output and make a tiny adjustment but I’ll avoid that if I can.

All buttons have been used, wiggled about and are working fine, all menus are displayed and basically it’s all working pretty much as it should be apart from some little adjustments. The shell is un damaged but a little tatty so a good clean up will assist here.

When taken apart the thing that strikes you is the lack of capacitors compared to the last item I worked on that was only 3 years older. I put some fine lubricant on the worm gear and the laser guide rail and also cleaned the laser lens with some Isopropyl (IPA)

I made a slight adjustment on the laser strength by using the Multimeter to get measurements across the laser pot.

The reading was very low, to what it would have been when new so, I made an adjustment to the higher end of the recommended scale but the unit didn’t like it and refused to recognise any Cd, so I’ve reduced it back to what appears to be it’s operating maximum, after 28yrs I guess the laser is approaching the end of it’s useful life.

Testing the laser

The sound quality has really improved, the unit still skips if it is knocked or shaken but as I’m intending to use the unit on a table or other surface I’m not really that concerned. It’s not as if I’m going to go jogging with it, no chance. To be honest I don’t think the anti jog system that was introduced for this purpose really came in until about 2000.

Put back together, I’ve now cleaned and buffed up the exterior, this is a nice little example of one of the lower end Discman units, but I’ve enjoyed working on it and getting to know a little more about how it works and fits together. I can put this one to bed now as a successful restoration, it’s going in my locker at work for listening to my old Cd collection whilst I’m doing the tedious paperwork or a night shift.

Thanks for passing by, I have another Discman post coming soon.

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 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.

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.

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.

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.

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.

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.

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.

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 🛑

Thanks for passing by. Always appreciated.

Capacitor plague

What the heck is that?

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).

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.

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.

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.

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!

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.

Minolta Dynax 5000i – Phoenix from the flames

It lives, it lives!

Phew, the donor camera arrived costing me the grand total of £3 sterling. It was badly damaged and I was doubtful that it would be any use due to its state.

However the pcb area and the lcd screen looked ok and after much cursing and burning of the fingers whilst de soldering and re soldering I put the battery in and there it appeared as if by magic…all clicked and clunked as it should and the battery indicator appeared on the screen.

I put the case back together and secured all the buttons to the frame and then connected the lens. Turned it all back on and hey presto all working fine. Focus’s well, flash works as it should, all counters and indicators doing what they should.

I’m happy with this camera now, just going to give it a wipe over and I now have a super little SLR for my collection. Will run a film through it when I get the time.

I can now say this camera is complete and in perfect working order.

Job done👍

(As an aside to this repair, the original owner was so surprised I got it working that he has asked if he can buy it back? That would be rather cheeky of me so I’ve just asked him to refund the cost of the battery and the damaged donor camera. He wants to get back into analogue photography, everyone’s a winner here, and a camera destined for the bin gets a new lease of life.) I’m happy 😃 👍

Minolta Dynax 5000i – Dead in the water

Well that’s annoying. I’ve stripped down the Dynax 5000i and found a terminal diagnosis for the power PCB and display screen.

There is a short circuit, severe corrosion from an old battery as well as the display screen being damaged where some of the fine contacts are destroyed rendering the unit useless at this stage.

Ok. I can strip down to individual parts, gain another 150 or so new screws and some parts that I may be able to use or sell on – or I can be a total numpty. I’ve decided to head down the numpty route and purchase a donor camera to repair this one. I’ll still get a load of spare screws following this route.

I’ve purchased a unit, it has cost me next to nothing and fingers crossed I can get one of them working and gain some spare parts for future use. I didn’t really want to pay out more but I take issues like this as a challenge and I’m committed to get this up and running.

My wife calls me gullible, what would she know bless her 😂

I’ll let you know exactly what arrives when the postman pays a visit.

Stay safe 👍

Minolta Dynax 5000i – Not working

If you remember back a couple of weeks I had this camera given to me by a family member. Not used in about 20 yrs still had a film in it as far as they were aware there were no issues with it.

I beg to differ…..

In lay man’s terms I think the term that should have been used is that it’s knackered (not working, kaputt a non existent camera)

I purchased a new 2CR5 6v Lithium battery from a well known supplier named after a rain forest. Motor buzzed, but no display or any other operation was available, first thought was to test the battery was not a dud, using the multimeter I proved this was not the case compared to the old battery.

So. What to do?

General census of opinion is to ditch this as mass produced tat and get another one on eBay for a couple of quid, the electronics are a known issue for many models of cameras from the 80s.

However, this site is not about just dump and run, I’m going to dig in and look to see if I can remedy the problem. I like a good electronic problem and hopefully I can sort this. If not, I’ll recycle the parts I’m definitely not throwing it away.

It’s a learning opportunity, and knowledge is king.

Thanks for passing by. You know it’s always appreciated 👍

Coronet F20 Coro-Flash

I’ve managed to obtain another old box type Pseudo TLR camera at a reasonable price in a very good condition, well, at least the pictures seem to indicate this, I’ll just have to wait until it’s in my hands to know for sure.

Here is some history on this camera, I will cite the reference at the end:

Introduced in 1950
Pseudo TLR
One speed rotary shutter +B
Use both 620 and 120 roll films
Flash sync
Built-in green filter
Body: metal

Coronet Box Cameras are medium format 120 & 620 film cameras made by Coronet in England.

Coronet was a British camera maker based in Birmingham. The company was formed in 1926 by F.W.Pettifer. It manufactured a variety of cheap box and folding cameras until 1967. After the war it worked together with the French company Tiranty to avoid French import restrictions. Several Coronet camera models were made in France, some with Boyer lenses, and some with instruction imprints in French. Coronet also had their own brands of film, including Corochrome.

The F-20 Coro-Flash by Coronet is a simple camera for 6×6 cm exposures, but one which offers a few twists on the usual box camera.
First, its centered viewfinder window and (small) folding hood give it a certain faux-TLR styling.
Secondly, it was designed (and proudly labeled) to accept either 120 or 620 film sizes.
Finally, it offers flash sync, for example when using its namesake Coro Flash flashgun.

Information on camera obtained from Camera-Wiki

This camera was in such a good condition that no maintenance was required. In fact it went straight onto eBay and sold within 7 days. Was a lovey little camera and commanded a good resale price.

Assessment and fault finding….will it work ?

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