This small LED torch came in for recycling. The batteries were stuffed. Cleaned the battery contacts and put some new ones in. It worked but not very well. It would flicker especially if the case was pressed. I took it apart, squirted some contact cleaner in the switch but it would still flicker. And then I noticed something.
The tab from the battery contact was shorting out to the LED PCB. It is thin metal so it bends easily. Either it was not bent down properly in the factory or it moved when the batteries were changed.
It was easily fixed. I bent the tab down and put a little patch of adhesive foam over it. We now have yet another torch that we can use and another item is saved from being recycled.
A Visione VISDVD5820 DVD player came in for recycling and since it has a HDMI output I thought I may as well have a go at refurbishing it. They are budget brand and as we will see you really get what you pay for. It seems to be a brand name used by Harvey Norman.
The batteries in the remote had leaked and caused really bad corrosion on one of the battery terminals to the point of almost completely rusting the retaining spring! Also, there were splatters of solder left on the circuit board from when the battery terminals were manually soldered in place in the factory.
A quick internet search showed that this fault has has happened to others. They sold for $29 and $18 and as low as $9! There is no point doing any repairs on it so off it goes to be dismantled.
It is a shame that this sort of poor quality equipment with poor quality batteries is being sold. This sort of stuff is short lived enough as it is because of the rapid change in technology.
I was pottering around at work on the Sunday night of a long Easter weekend and decided to fix a set of tool drawers that came in for recycling. Yep, we get all sorts of things coming in for recycling!
Ecotech Services has needed a set of tool drawers for a while and I have been looking out for a suitable second hand bargain. And then these turn up!
The bottom drawer was a bit hard to close. Turns out the drawer runner had lost its bearings. All but one of the ball bearings on the runner were missing.
What are the chances of getting a new runner for it? Possibly not good but repairing is usually the first option for me. So I need some 3.8mm diameter ball bearings to fix it. We have got things that look like short drawer runners in stock that have been salvaged off all sorts of things, including monitor stands and photo printing kiosks. They would a good source of replacement ball bearings. The first one I pulled apart had 4.8mm ball bearings but I got lucky on the second one. It had the 3.8mm ball bearings that I was after.
The drawer was easy to get out. There are two plastic clips that act as end stops and can be moved to get the drawer out.
I cut the end off the sacrificial runner to get the ball bearings out. I then had to remove the end clip on the tool drawer runner to take out the ball bearing holder and I then added the replacement bearings to it. I used bit of grease as a “glue” to keep all of the bearings in place while getting it back on the runner. It was then a matter of putting the runner end clip back on and sliding the drawer back in.
This is the ball bearing holder now with its full set of bearings.
Ecotech now has some better tool storage in our mechanical work area!
Some manufacturers are just not learning from past manufacturing mistakes. Or they just don’t care about how long the stuff they make will last.
One of the faults with some electronic equipment is a glue used in manufacturing that becomes conductive with age (or age and heat). I first found out about it back in the 1990s when I was repairing CRT computer monitors at Phillips Electronics. It caused all sorts of faults.
Fast forward to the 2020s and there is still problems with conductive glue. Here is the insides of a Digistar DS-612T set top box.
Glenn is testing the faulty set top box.
The unit appeared dead but it eventually produced a display but that was about all. There is conductive glue in the power supply and around a logic ic. We got readings as low as about 1.5MΩ which will cause problems in any high impedance circuits.
This MS-7LA calculator came in for recycling last year. It did not power on.
It is the holidays at present so I thought I would do some holiday hobby work (repairing things is one of my hobbies).
I undid the three screws on the back of the calculator and the back cover come off fairly easily. The leaky battery was easy to spot. I cleaned the circuit board and put in a new battery. Still no go! On closer inspection the circuit board pad looked a bit tarnished. I then spotted the completely corroded PCB track that would have been where the interface between the anode and cathode of the leaky battery was positioned.
I removed the battery clip, cleaned the anode terminal, and added a wire link (the blue wire in the photo below) to fix the corroded track.
With the battery back in the calculator was back in operation.
That all took me about 20 minutes. At our current labour rates that would have cost a customer $26 for the labour alone and at our current minimum repair fee cost it would have been $35. The battery costs $3.25 or $5.00 for one of good quality.
You can buy a roughly equivalent calculator of a well known brand for less than $4.00. The current Casio equivalent sells for $20 but I can probably only get $5 for the one that I repaired.
Had a no name brand battery charger come in for recycling. I set it up on the bench to test it. It powered up but after a bit it turned off. I took the thing apart. Pretty easy to do. Four screws at each end holding the slit extrusion case together and one holding a couple of TO220 packaged devices in place. The earthing was far from ideal. It was just tucked under a self tapping screw and none of the paint had been removed.
So of course the thing will not play up with the covers off! I set it up with a battery to check the charging. That all looked good.
(I’d better not mention here that I put the battery on with reverse polarity and blew the output fuse. Hey, I blame the fact that I did not have a black jumper lead. Yeah right!)
I moved it a bit to look at the front panel and there was a spark and it stopped working! “Oh s**t!” I thought to myself “what have I shorted out?”. Powered it up again and it still did not work. Better do some fault tracing. And then it sparked again. Ha! It is sparking in the Faston style connector. I was lucky that it had one of the clear insulating boots over it so I could easily see the sparking.
The connector had been crimped but the wire gauge was too small for the connector so they just soldered them. In this case there is a big solder blob that got nowhere near the wire. So it was a very loose connection.
Not only did they cut corners with thin wires but they also threw these things together really quickly. The solder hardly melted before they moved on to the next one. And there was probably no quality control or burn in testing.
Such a shame.
I did a decent job of soldering it and then added some proper earthing.
I had a Megger MIT220 meter come in for repair from Dells Appliances, our related company. It was not giving a reading. It was an easy fix.
The wire broke!
The wire had broken of the test lead terminal inside the meter. After taking it apart it was obvious what actually caused the fault. The metal contact of the terminal could rotate inside the terminal housing by about a millimetre either way. With usage the solid core wire eventually broke due to metal fatigue.
I did a permanent fix by gluing the contact in place.
This is a case of poor design. They did a nice job with tying down the two wires so I don’t think it is something that could have been overlooked. Also design engineers should realise that solid core wires should not be used where there is any possibility of movement.
The electronics repair industry in New Zealand has been in decline for the past two or three decades for various reasons including the flood of cheap commodity goods, poor support from the manufacturers, and rapidly changing technology.
One indication of the decline of the repair industry is the plight of component suppliers. The company that I first worked for, TESA (an abbreviation of Television Engineers and Supplies Associates), has been subsumed into Lacklands. And now, as of last month, Trade Tech, one of the other large component suppliers, has gone into liquidation.
The annoying thing is that I placed an order for some parts with them not knowing that they were in liquidation. Only three parts out of an order of ten turned up. I am still waiting for the remaining seven after about three weeks. I might not see the rest of the parts.
In Hong Kong they have electronics repair shops next to the footpath. Here in New Zealand most of suburban radio and television repair shops closed down years ago. Image: Wikimedia Commons.
