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SERVICEMAN’S LOG Another busman’s holiday Dave Thompson I recently travelled to Australia, the spiritual and physical home of Silicon Chip magazine. Sadly, I did not get to stop in and meet the people I have been working with for many years because my wife and I were headed to Western Australia, which is literally on the other side of the continent! One day, I’ll make it there but for now, we had a pressing need to get to Fremantle and visit some of my wife’s relatives, many of whom emigrated there after World War 2. They are all very elderly now and that was one of the reasons to get there and touch base with them. Fortunately, we made it in time, and all was well. Although Australia and New Zealand share a lot of history and have many things in common, visiting Australia is always like stepping into an alternate reality for me. Many things there are just done differently, and the philosophy among the people is somehow very different. This is more obvious when going to the many states across the vast space that is Australia – for example, the people in Darwin are typically different from the people in Melbourne or Sydney. Likely this is because many of the original immigrants brought their own cultures and customs to their new homes, wherever they decided to settle in this vast country. Fremantle has a large population of ex-pat Croats, and my wife has four aunts and many other relatives still living there. We were going to visit one aunt in particular who is ailing, which made it a very pressing and poignant trip. Where we live in Christchurch, New Zealand, there are hardly any people from Croatia. So for her to walk into a deli or a market in Freo, or in one case, get into a taxi, and speak Croatian to the driver, is a real plus for her. 88 Silicon Chip That cultural balance aside, there are many other subtle differences between our two countries, or at least things that I noticed. In parts of Europe, for example, most people who build a house use a standard type of shutter/door arrangement for all their windows and doors. They likely come in a few specific sizes, and homes are constructed to suit those sizes. A case of shutter envy I have often wondered why we don’t have those shutters and doors here in New Zealand. They are brilliant, with many features that enable opening them in many different ways and even shutting them to complete blackout level. Not only are these shutters and doors very secure, and almost impossible to open from the outside, they are versatile enough to let the outside world in without compromising security. Anyway, you are likely wondering what all this has to do with the Serviceman’s Curse – which I am sure you knew was going to make an appearance sooner or later. I can run to another country, but I can’t hide! It seems I cannot travel anywhere in the world without having to fix something, or even think about fixing something. All this talk of shutters and doors and what-have-you brings me to the point. A lot of homes – many of which are so-called spaghetti mansions (built in the style of Mediterranean houses) – in Freo have the same hardware installed as I saw in Europe. No doubt the people who emigrated here brought this stuff with them. This hardware just doesn’t exist in New Zealand, more’s the pity because I would have this installed in my house in a heartbeat. I suppose I could import it, but the cost would be prohibitive. These things weigh a tonne, and as I’d need a house-sized lot, it was not really an option for us to import them here. They are obviously available in Western Aussie, though, because many of the houses I saw there had them. Usually, these shutters are manually operated, with a canvas-type ribbon on a spindle that can be pulled either way to raise or lower the shutters. It’s a simple system that has likely worked for a hundred years. Australia's electronics magazine siliconchip.com.au Items Covered This Month • A trip over the Tasman • Repairing a bulging iPhone 7+ • A shocking experience • The dangers of lightning Dave Thompson runs PC Anytime in Christchurch, NZ. Website: www.pcanytime.co.nz Email: dave<at>pcanytime.co.nz Cartoonist – Louis Decrevel Website: loueee.com Now, though, we have this electricity thing to make life easier. No more pulling on ropes, ribbons or strings; now we can just hit a switch and the shutters open or close. Obviously, this requires motors and actuators to make it all happen, and over time these have been introduced and have replaced the manual methods of yesteryear. A fault rears its ugly head So, one of the places we visited has these electrically operated shutters. There was a switch on the wall inside the lounge, which looked like a light switch, that operated the shutters, up or down, depending on the position of the switch. Except the switch didn’t work properly, and the owner complained that it often didn’t open or close the blinds properly. He commented that often, he would have to toggle the switch several times to actuate the shutters, and that it was becoming more and more of a problem. To my serviceman’s mind, I immediately thought that either the switch or the actuator was the problem. I know what you’re thinking, is it the switch or the motor? I’m way ahead of you; it could be either! So here I am, seemingly now on a busman’s holiday, trying to figure out what’s going on with this shutter system. Of course, the owner is telling me not to worry about it, that I’m a guest, and only here for dinner, but what would any self-respecting serviceman do? Looking the other way isn’t really an option. I can’t sit at this guy’s dinner table and eat his very well-cooked food knowing that there is something not working properly. I mean, it is the Serviceman’s Curse, not the Serviceman’s Gift! The first thing after dinner was to check out the other shutters and see how they worked. All operated normally; it was just this one in the main dining room that didn’t. As it was the most used, it likely wore out quicker than the rest. Each shutter has a covered part at the top where the motor/actuator and the rest of the gubbins live. These covers were easy enough to get off as they were just screwed on and have a weatherproof seal to keep the worst of the rain out. As most of the shutters were installed under the eaves of the house and were well out of the way of the weather, it was kind of moot, but of course the seals had to be there. So, during dinner, all I could think about was this problem. I thought the problem must surely lie with the switch. When it worked, it worked well, and the shutter descended and opened up once it was going. I went around the house siliconchip.com.au and tried all of them – this one in the dining room did feel a little spongy. Just less precise in its operation. Since they’d been installed 25 years ago, it is normal to assume that something may have worn out. My guess was the switch, rather than the motor because it didn’t feel ‘right’. All the others around the house were crisp in their actions and just felt right. I offered my professional opinion that the switch was the problem and that we should change it for a new one. This was not going to be a problem, as these switches are a standard item and available from the various window and shutter retailers dotted around the landscape. Our host said he would take me to one of these places the following day, so at least we could enjoy a nice meal that night without the Curse intervening! Time to switch the switch He was good to his word, and we soon sourced a new switch. Now it was just a matter of putting it in without killing myself. Fortunately, the electrical systems are very well-thought-out and simple. We also have fuse boxes and breaker panels in New Zealand, but they seem far less standardised than the ones in Australia. The house is an older-style brick place, I’m guessing built in the 1960s, and the power breaker panel is easily accessible and well-labelled. In New Zealand, we just guess which breaker goes where and hope we don’t get zapped! One of the good things about renovating this house I own now before we moved in was that I could map the entire electrical system and produce a diagram showing what breaker controls what circuit and how everything is connected. I’m not sure why sparkies don’t do that here – or maybe they do, and I just haven’t seen it. I mean, I have seen breaker panels with those old black and gold stickers on them showing hot water or outside lights or whatever. Still, it seems to me that many homes – at least the ones I’ve lived in – have had bits added or removed over time and many times the stickers no longer refer to the correct circuits. It must be a real headache for electricians to walk into a place and have to work out what goes where. This could be down to the cowboy culture here, but I didn’t see that in Western Australia, at least, not in the house I was visiting. Everything was labelled and sectioned off in a proper and easily accessible cupboard, and I was pleasantly surprised. Most breaker panels in the homes I’ve lived in are set high up near the roofline and required a stepladder or at least a chair to gain access. Perhaps the theory was that putting Servicing Stories Wanted Do you have any good servicing stories that you would like to share in The Serviceman column in SILICON CHIP? If so, why not send those stories in to us? It doesn’t matter what the story is about as long as it’s in some way related to the electronics or electrical industries, to computers or even to cars and similar. We pay for all contributions published but please note that your material must be original. Send your contribution by email to: editor<at>siliconchip.com.au Please be sure to include your full name and address details. Australia's electronics magazine February 2025  89 it out of reach was the safest method to ensure idiots like me don’t mess with it! This one in WA was right in front of me and I could just open it. Luxury! So, we had the switch and now we had to disable the active circuit that the shutter was on. Despite the labelling and easy access, we still had to do some trial and error to ensure we killed the right one. It would be embarrassing in the extreme to end up frying myself at our host’s house! What would the neighbours think? The next problem was that all my tools are thousands of miles away across the continent and the Tasman Sea – as if that little bit makes a difference. My host said he had some tools in the garage, and I was free to use any of them. Tools for fools Great! Until I checked the tools. These were the kind of things I would find at a $2 shop or maybe a car boot sale at one of the markets Australians love so much. I have to admit, I too was seduced by the markets. The Fremantle Market is huge and a joy to walk through. If the thousands of other tourists are anything to go by, they all love it as well! But, and here’s a big but, the tools I see on sale there are the single-use type. I’m sure you know this level of excellence – you buy a Phillips screwdriver, then try to undo a screw with it and it strips like it was made of Plasticine. Have these manufacturers never heard of hardening? These were the kind of tools my host had in his garage. I guess if I was very careful I might be able to use them to change a switch plate, but, well, you never know with these things. The guy who installed it likely used a proper screwdriver and smoked those screws so tightly that I’d never get it undone using a waxworks screwdriver like this one. Like any serviceman, I need tools, so the day after we got the switch we went back to the same place and bought two screwdrivers, a flat head and a Phillips head driver. 90 Silicon Chip You used to be able to service an entire car with just these two tools (OK, maybe also a shifter, or Crescent as we call it here), so changing a switch plate shouldn’t be an issue. I also bought a mains power detector, one of those things that looks like a pen but beeps and flashes its LED when near a mains circuit. It always makes me feel happier working on wiring when I don’t hear those things beeping. I have owned a few over the years, but the early ones are a bit dodgy now, and I don’t really trust them anymore, so this will be a nice addition to my tool set. I will leave the drivers with the owner of the house – I already have several decent drivers, and in the future he can make use of them. So, with the assurance that the circuit was dead and there was no chance of me being cooked along with dinner, I removed the dodgy switch and simply replaced the old one with the new. That just involved pulling the power leads from the faulty one (which, as I assumed, were really tightly fixed) and putting them into the new switch. I powered up the circuit with the switch hanging off the wall – yes, I know, a dangerous practice, but in my defence, I am a cowboy from New Zealand after all, so I tried it before buttoning it all back up. It worked perfectly. That was good news. I didn’t really want to be disassembling an electric shutter mechanism in the break between the main meal and dessert! I replaced the switch assembly, which of course fits perfectly because people do things properly in Australia, rather than sometimes multiple different types of switches in New Zealand that use different mounts and standards. I guess we really are the wild west out here. In some ways, that can be a good thing, but standards are what make the world go around, so it was nice to see them being used in Australia. I am, of course, talking about Western Australia. Perhaps things are different in the other states. I don’t know, so I will rely on others to put me right on this. Anyway, the shutter now works well (and without lots of cursing), and the host was generous in offering me a nice dessert with some beautiful wine to finish with, so it all worked out in the end. Australia's electronics magazine siliconchip.com.au I love Australia and have visited there many times all my life. Admittedly, there have been long periods between my visits, but I have family there and a love for the country. I wish I could visit more, but really, fixing everything there would be a real challenge for me. So perhaps it is better I let all the amazing servicemen already there do it, and then I can retire, and maybe pop over to see how things are going! iPhone 7+ repair My youngest son’s iPhone 7+ was bulging badly due to the failing battery swelling. This same thing happened to my Samsung Galaxy tablet; that repair was featured in the October 2020 Serviceman’s log (on page 65; siliconchip.au/Article/14609). This iPhone was originally bought by my younger daughter in 2016, so it was now eight years old. Until now, it had not required any repairs. The other problem with the phone was that it was saying that it did not have a SIM, even though one was present. I thought this might be related to the bulging. I first looked on YouTube to see if there were videos on replacing the battery. Finding a few, I selected the one that had the best tutorial. Then I ordered a new battery, tools and a The bulging iPhone battery (left) and a photo showing how it was removed new screen protector from eBay (the exist- from the case (right). ing screen protector was badly cracked). The parts arrived, but there was no screen seal, so I had to the screen seal, which wasn’t quite wide enough for the order that separately. With everything on hand, I set about phone, but I managed to get it in place successfully. So it dismantling the phone. was finally time for reassembly. I first removed the two pentalobe screws at the bottom I reconnected the screen, then the battery and replaced of the phone and then carefully prised up the screen. This the two shields. One particular trilobe screw caused an job was made easier by the fact that the battery had lifted enormous amount of trouble; it refused to screw in and it on both sides, but had not broken it, which would have kept flicking out and vanishing. I lost it six times in the added considerable cost to the repair. process, with it landing outside the phone the first few With the screen free, I opened it up on the right-hand times, then inside the phone. side like a book and used a box to hold it while I worked I decided to try a different screw in that location and I on removing it. I removed the two shields with a trilobe had success with it, so I moved the troublesome screw to screwdriver, then flicked out the connectors for the battery where I had removed the replacement screw and this time and screen. I could then put the screen aside and work on it screwed in successfully. It is unclear why this screw was removing the battery. giving me so much trouble, as it was the same size as the The battery is removed by first prising up the adhesive at other one. [It may have been slightly bent by the bulging its end and then pulling the adhesive out carefully while battery – Editor] not breaking it. There are three adhesive strips that have With the screen and battery connected, I switched the to be removed in this manner (see the photo). phone on before assembling it, to make sure that it worked, With the adhesive removed, the battery can be lifted which it did. It was now searching for the network but not free of the phone and preparations made to install the finding it. new battery. The new battery did not come with adheEither the phone had a fault, which I thought unlikely, sive strips, so I cut two lengths of double-sided tape to or the SIM was faulty. I turned the phone off, removed secure it in place. the SIM, cleaned it and put it back in, but it still did the It is very important to connect the battery before adhering same thing. it to the phone, to make sure that it is lined up correctly. I put the SIM from another phone into the iPhone 7+ If it were secured first and the connector does not line up and it immediately found the network, so the phone was with the logic board connector, that would be a big problem. in working order. Putting the SIM from the iPhone 7+ into Once the battery is secured, it is disconnected again for the other phone caused it to come up with the message installing the screen seal. I ran into some difficulties with “Invalid SIM”. So the SIM was definitely faulty. siliconchip.com.au Australia's electronics magazine February 2025  91 I fully fitted the screen, pressed it down firmly and carefully around the edges and put the two Pentalobe screws back in the bottom of the phone. I then removed the old cracked screen protector, cleaned the screen and installed the new screen protector. The phone had a case which was not in very good condition, but as it happened, my wife had found a new case at an op shop for $1, so with that, the repair was complete. We just needed a replacement SIM, which my wife picked up at Officeworks when she was nearby. With the new SIM now on hand, I rang the carrier to go through the process of changing the number over to the new SIM. After the process was completed, the consultant said it would take 1-4 hours for the new SIM to become active. However, as soon as I inserted it and switched the phone on, it was active. My son was very happy to have his phone back and now working well with its new battery. B. P., Dundathu, Qld. A shocking experience! This shows the basic capacitor discharger I made, which I should have used right at the beginning of the repair! Also see the Capacitor Discharger project in the December 2024 issue (siliconchip.au/Article/17310). 92 Silicon Chip I had a bad electric shock the other day. I hadn’t suffered one for years, so complacency had obviously set in. A friend had brought in his electric motorbike charger and battery. The bike can be used on motorways, so the battery is huge, along with its associated switch-mode power supply unit/charger. The switch-mode power supply unit (SMPSU) was giving no output, so I took it apart. My friend assured me he hadn’t plugged it in for a week. Looking inside, I found that it was a common SMPSU problem: bad lead-free soldered joints around the enamelled wire from the ferrite transformer. This usually happens when the enamel hasn’t been fully removed before soldering. Also, lead-free solder has inferior wetting properties and its brittleness results in cracking from the high-­ frequency vibration due to magnetostriction in operation. I soon set to work, scraping off the burnt flux with a scalpel around the joints to get a good look. BANG! I got a massive DC belt from one arm to the other, very nasty, like an old Fender valve amp HT rail but worse. The scalpel was nowhere to be seen; luckily it wasn’t embedded in my friend’s head! I shouted, “that felt like 350 volts!”. I got my meter out and shakily measured between the pin I was scraping and the chassis. I thought (belatedly) that I had better discharge the main smoothing capacitors, of which there were three in parallel. So, stupidly, I got my nice insulated Bahco Ergo pliers out and shorted the pins. BANG! It blew one of the tips off. 4500µF of capacitance charged to 350V is a lot of energy (E=½CV2 so 275J)! Still shaking a bit, I continued and fixed the joints. I wasn’t going to be beaten by this modern ‘disposable’ electronics. Having fixed the bad joints, I soldered a bleeder resistor of 39kW 5W across the caps and switched it on. The LEDs lit up and it gave the correct 80V DC output at 10A; perfect. My friend thought the whole thing was most entertaining! It’s a good job it worked. He’s now enjoying his bike, and I found the scalpel stuck in the skirting board a week later. Morals of the story include: • Don’t assume something is discharged, even if the client says it hasn’t been switched on for a week! Australia's electronics magazine siliconchip.com.au • Don’t use a metal Swann Morton scalpel for repair work; use a plastic-handled one instead. • Don’t assume all SMPSUs have bleeder resistors wired across the main smoothing capacitor bank. Even if it has, the resistor may have become open circuit. This circuit didn’t have one because the continuous dissipation would be high and reduce its efficiency. • Measure the voltage across big capacitors as soon as you open the case and before you start working on the PCB. If they are charged, discharge them slowly with a bleeder resistor attached to insulated test probes. • Remember the ‘left hand in pocket’ rule; don’t make an easy current route through your heart. If you must hold the metal enclosure or chassis while working on it, physically clamp it or insulate your hand. Even relatively mild shocks involving the heart can lead to cardiac arrhythmias. • There’s nothing more embarrassing than getting a small shock and wetting yourself, then getting a massive one because you are standing in a pool. I know because I once did it in front of a load of students! It became a standing joke; I defused it by having a spare pair of underpants in the first aid box. J. R., Llandrindod Wells, Wales, UK. What lightning can do Mention was made a while back about the damage lightning can do. Here is my experience. Back in 1960 during my apprenticeship, I was called to a TV fault in a country home. On arrival, the owner told me what had happened. Lightning struck a power line down the road, it got into the house and blew all the fuses in the switchboard (they were actually fuses in those days). It also got to the TV antenna, and he showed me how the 300W ribbon had sprayed the fibro wall with molten copper. I went to the TV set and saw the ribbon had melted off the input terminals and was dangling in midair. I took the back off the set and saw that the on/off switch on the back of the volume control had been vaporised, and the mains wires were also dangling in midair. After replacing the volume control and 300W ribbon, the set was functional but the picture was snowy. Further investigation showed the input balun in the tuner was burnt out. After ordering another one and putting it in, the set was back to normal. I doubt if a modern TV would be as repairable as this one was after a lightning strike. SC T. V., Morayfield, Qld. siliconchip.com.au Australia's electronics magazine February 2025  93