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SERVICEMAN'S LOG Fixing a “Cheap as” set of cans While there’s a huge range of cheap electronics available online, some of it really is ‘cheap’. It’s unfortunately not uncommon to receive goods different to what you paid for. Sometimes I wonder whether the time lost dealing with all this is worth the money saved. I don’t know about the rest of you, but I’ve made good use of cheap Chinese imported goods. I discovered AliExpress many years ago but I was initially hesitant to send any money off in that direction. After all, early incarnations of Alibaba and similar B2B (business-tobusiness) sites were ill-policed and well-known as a scammers’ paradise. But after I dipped my toe into the warm waters of low-cost electronics, I became comfortable with the idea and by now, I’ve ended up throwing a lot of cash eastwards. I have now completed many hundreds of trades, often finding and purchasing components I haven’t been able to find locally for ages. For the most part, it has been a painless experience. These days especially, with escrow-type payments and a credible seller feedback system, buying something from any of China’s online merchant sites is simple and (mostly) without fear of being burned. This is not to say everything always goes smoothly; once, after much toing and fro-ing with a vendor via the messaging system, I ordered a relatively expensive circuit board for a client’s dead flat-screen TV. Instead, what turned up in the post was a very cheap Fitbit-style device worth a fraction of the cost of the PCB. When I went back to the vendor to get an explanation, I got no answer, despite repeated and increasinglypointed messages. Eventually, I decided that he must be purposely trying to exceed the then-30-day buyerFor those not in the trade, “cans” is a common nickname for headphones. 62 Silicon Chip protection period, after which he’d be paid regardless, unless I lodged a complaint first. The guy eventually did reply, claiming the error had been made at China Post and was thus out of his hands and I should get hold of them to sort it out. He also requested I mark the goods received and accepted so payment could be made. Since I didn’t come down in the last shower, I declined his generous offer and told him that unless he sent me the board I’d ordered, I would lodge a complaint, apply for a full refund and give negative feedback, something most vendors try to avoid at (almost) any cost. After hearing nothing more for a week, I went ahead and filed a dispute and got my money back. Unfortunately, he was the only vendor I could find selling that particular PCB, so that was the end of that. However, this sort of event is quite rare, and I’ve only had to deal with a handful of disputes over the years. Caveat emptor For the most part, the products depicted on the site are as-described, and aside from the odd purchase taking over six weeks to arrive, most transactions are hassle-free, and everyone comes away happy. That said, B2B sites can still be a trap for the unwary. A certain amount of awareness and a healthy dollop of common sense goes a long way to avoiding potential embarrassment. In the early days, I learned the hard way. For example, there were many listings for ‘iPhones’ priced considerably below what you’d expect to pay Australia’s electronics magazine Dave Thompson Items Covered This Month • • • Headphones in one ear, regret in another Digital photo frame repair A self-discharging Suzuki Vitara *Dave Thompson runs PC Anytime in Christchurch, NZ. Website: www.pcanytime.co.nz Email: dave<at>pcanytime.co.nz here. The ’phones certainly looked like iPhones, complete with the Apple logo and product information stencilled on the case, and no wonder; the images were those of actual iPhones. But in reality, the item for sale was a locally-produced clone, and not a very good one at that. The phone I received was nothing like the one in the photo. Not only was it nowhere near as well-made as a real iPhone, but it also was low-spec, didn’t run iOS (it used some version of Android) and couldn’t be used with an Apple account, run iTunes or use any other apps from the Apple Store. I ended up giving it away to a visitor to the workshop who expressed interest in it; I think he threw it in the bin not long after that. Thankfully, this type of deception is now rare, and dodgy vendors are quickly reported and removed. It still pays to be cautious though, especially when something seems “too good to be true”. Those new to these sites might think some of the advertised products are fantastic bargains, but more experienced visitors know that most of the time genuine big-name products are not that much cheaper (if at all) than those sold by local retailers or Western online vendors. At least here we are protected by consumer laws and warranties, which is not always the case with foreign purchases. Even servicemen sometimes fall into traps A while back I was in the market for siliconchip.com.au a new set of headphones, and I purchased a pair of Sony wireless Bluetooth “over-ear” style headphones from a local big-box store. I couldn’t wait to get home and try them out, but was extremely disappointed when I plugged them in and discovered that while they were well-made (as with most Sony products), and comfortable, the sound quality was abysmal. I was annoyed with myself more than anything; the only store who carried this particular model of headphones didn’t have a “try-before-youbuy” stand like many others (policy, they said), so I’d thrown caution to the wind and relied on price-point, brand recognition and faith that being Sony, they should be good quality. Before I discovered the benefits of decent earplugs, I’d had my hearing pounded by years of exposure to power tools, high-octane model-aircraft racing engines, playing in bands and attending too many rock concerts. But I can still differentiate between what sounds good and what doesn’t, especially when using headphones. So I took them back to the store and had a stand-up argument with the teen-aged ‘manager’ who insisted that either I hadn’t charged the battery enough or that I expected too much fisiliconchip.com.au delity from a Bluetooth wireless system. Apparently, this was no basis for returning them. I politely informed the guy that the battery was well charged and that the Bluetooth earbud headphones I bought from China for a few dollars to use with my mobile phone had excellent fidelity and outperformed these expensive Sony ‘studio’ ’phones by a wide margin. I stood my ground and asked to try out another set of the same model headphones, in case the originals were faulty, but the manager informed me Sony wouldn’t allow them to open a sealed box without a sale, so I demanded a refund instead. While I eventually got my money back, the store made me jump through hoops and wait for more than a fortnight while they sent the headphones back for ‘testing’ and got the warranty sorted. My complaints that this whole process broke our consumer-guarantee laws fell on deaf ears (LOL), but I was vindicated a few months later when I read reports that this chain of stores had been prosecuted, found guilty and substantially fined for dozens of similar breaches of consumer regulations. I certainly won’t be shopping there ever again. It’s no wonder then that I (and others) increasingly shop online, often from overseas vendors. Not only do I avoid being patronised, but I also cut out the greedy middle-man altogether, and this makes my hard-earned dollar go further. However, the government has caught on – most likely due to lobbying by campaign-funding, cry-baby bigbox retailers who constantly whinge about an ‘uneven playing field’, despite them having gouged consumers blind for years – and are intent on Servicing Stories Wanted Do you have any good servicing stories that you would like to share in The Serviceman column? If so, why not send those stories in to us? 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 June 2019  63 introducing an “Amazon tax”, like in Australia. This will add GST and other local taxes onto products valued at less than $1000 purchased from overseas (products valued $1000 or more are already heavily taxed), though I’m not sure how they are going to coerce Amazon, Bangood or AliExpress into collecting Kiwi taxes. I guess that these online sellers will merely do what they’ve done in other countries whose über-greedy governments slap taxes on small overseas purchases and either stop selling here altogether or limit what products are sold here. Excellent! Going on a shopping spree In the meantime, I’m buying all I can. Lots of cheapo modules like Arduinos and accessories, valves, amplifiers, guitar parts, shoes, clothes; you name it, I’ve bought it! One of these purchases was a pair of headphones. The listing on AliExpress showcased some Bingle-branded wired models (with USB and 3.5mm audio jack connectors) that ticked all my purchasing boxes. They look very similar to those (typically) green ‘aviator’ or military-style noise-excluding headphones you often 64 Silicon Chip see pilots wearing. As I’d tested or repaired hundreds of ‘real’ versions during my time at the airline, they have the benefit of familiarity. They also possess a certain retro-cool. But all was not as it seemed; while the ’phones in the product images were almost certainly the genuine Bingle versions, the ones that arrived here almost certainly weren’t. They looked similar, but the buildquality said otherwise. The seller had also offered to ship the product without retail packaging because the increased size makes postage more expensive. More likely the product isn’t genuine and the packaging is non-existent or a plain white box. While some sites offer the product in retail packaging, the cost is usually higher, perhaps to dissuade buyers. Not all sellers will be hawking fake products using this ploy, but due diligence is recommended! In this case, I chose to get the packaging, just in case I wanted to re-sell the ’phones at some point and duly paid more for the privilege. When the ’phones arrived, the typical yellow tape and a single sheet of waferthin bubble-wrap packaging hadn’t prevented the box from being bashed in transit to roughly the shape of Australia’s electronics magazine the ’phones inside anyway. Lesson learned. While they weren’t the real thing, they did at least sound quite good and were reasonably comfortable to wear. Nonetheless, I had much remorse, as well as annoyance at myself for falling for the dodge. I filed a dispute but only asked for half the purchase price back. For better or worse I had a set of ’phones, and returning them would have cost me more than all this was worth – a fact I’m sure many vendors are wellaware of. I left feedback accordingly, leaving no doubt about the authenticity of the product and put it all down to experience. I note that these ’phones are no longer being sold on AliExpress where once they were all over this site. I wonder why… And this was how things remained until one day the ’phones stopped working on one side. Actually, the detachable boom mic stopped working first, almost from day one, but since I wasn’t using it and had removed it anyway, I wasn’t too bothered. But when the right-hand driver suddenly stopped, it was time to roll up my sleeves and break out the screwdriver set. Time for a repair Some headphones I’ve worked on in the past have been a real pain to tear down, being tightly clipped together with breakaway plastic tabs. Getting them open is semi-destructive, and they have to be glued back together. Surprisingly, these headphones were all screwed together, and with standard fasteners – none of those ridiculous anti-tamper things to hinder my progress – so disassembly was a doddle. The way into the headphones is typical of most; remove the cushioned earpads by working around the edge of the earpad mounts, gently stretching the material clear. Once off, the screws holding the mounts are revealed; there were four on each side to take out. To make things easier, I removed the thumbscrew-style height adjusters sitting above each pod (or “can”) and released them from the headband assembly. The two cans were still connected by an audio cable, which runs through the hollow headband padding, but after removing the stiff metal part of the headband, I could at least flex everything and work on each side without siliconchip.com.au the other getting in the way. I began with the left-hand pod, as this is where the main audio cable enters and any electronics should be located inside it. After removing the outer earpiece ring, there were three longer screws underneath holding the two shells of the can together. Once the screws were out, the two halves easily separated. Inside was a sizeable PCB containing what I assumed to be an amplifier and a USB decoder. The 3m long main cable enters the bottom of the pod through a plastic strain-reliever and sports USB and 3.5mm jacks (one 3.5mm stereo jack for sound input and another mono jack for microphone output) at the far end. A second, much thinner cable exits the top of the can through a grommet and heads off through the headband to the other pod. The shielded main cable contains eight tiny wires, and the thinner cable has three, all colour-coded and terminated to their respective solder pads on the PCB. Or perhaps I should say, they should be terminated; I could see three wires floating happily in the breeze, while the others looked to be tack-glued to the PCB with large, dull solder blobs. Whoever put this together should go back to soldering school. It was a wonder it worked at all! Before doing anything, I had to figure out which wire went where on the PCB. As is typical on cheap electronics, there was no information screen siliconchip.com.au printed onto the board. Usually, if leads break free, they are relatively easy to match using a microscope and a basic comparison with their distinctively broken ends; if just not connected properly, this can be a bit trickier. Luckily, in this case, I could match each wire to an impression in the solder blobs enough to make an educated guess. The type of wire used in the cables is prevalent in audio gear. Each multi-stranded wire is very fine and well-insulated, but not by an obvious plastic coating like other types of wire. Each wire also has very fine cotton or synthetic threads running through it, likely for strain relief, which along with the insulation material makes soldering it a real challenge. Even with a decent amount of heat, solder just beads and runs off. No wonder it was just globbed together at the sweatshop, er, I mean factory. In the past, I’ve had to burn the insulation off to be able to solder it. In the early days, I used a match; now, I use a small gas torch, the kind used for jewellery or micro-welding. A brief touch to the end of the wire causes the thread and insulation to instantly burn off. A quick pinch with a damp sponge removes any crispy remains, leaving shiny wire behind. While solder sticks to this cleaned surface, I also use a touch of flux to help it ‘sweat’ through. While I was at it, I also re-soldered the other connections, prepping and cleaning wires and PCB pads before tinning them all with fresh solder. It was simply a matter of a quick touch with the iron to re-connect everything and a sound-check confirmed I had audio in both cans and a working microphone. Reassembly was as easy and pulling them apart, and I still use these ’phones today. Not exactly Bingles, but OK for cheap Chinese imports. Digital photo frame repair B. P., of Dundathu, Qld is another person who is willing to put in a little bit of effort to fix a device, even a fairly cheap one, rather than throwing it away and buying a new one. And as he says, sometimes the faulty component is obvious and the repair is not too difficult. You just need to be willing to have a go… Australia’s electronics magazine June 2019  65 A few years ago, we bought a used 15-inch digital photo frame on Gumtree. Initially, I had some problems setting up this unit, as it didn’t want to display the photos on the SD card and reverted to showing the stock photos on the inbuilt memory. I solved this by deleting the stock photos and putting our photos on the inbuilt memory. It then performed well for a few years. But recently, my wife commented that she was having problems getting the photos to display and she would need to power the unit on and off several times before it started working. This went on for around a week; then it just stopped working altogether. I observed that it would initially show the splash screen for around one second, then a blank screen. I tried a different plugpack power supply in case that was faulty, but nothing changed. So the unit itself was faulty and I suspected that it might be a dud capacitor. I started opening it up by removing the 12 #1 Philips head screws from the back cover, which gave access to the inside. I then disconnected four plugs so I could remove the back completely and inspect the circuit boards. It didn’t take long to spot the faulty electrolytic capacitor on the inverter board. The bung had been pushed out the bottom of the 220µF 25V unit. That was apparently the problem, and I thought it would be an easy fix. Usually, I would use a salvaged capacitor for repairs like this, but because this capacitor was lying down, I would need to use a new capacitor with long leads. Because of the limited space inside the unit and the fact that 66 Silicon Chip the inverter board has a plastic cover over it, I couldn’t mount the replacement vertically. With a new capacitor fitted, I reinstalled the inverter board and went to re-connect the four plugs that I had disconnected earlier. But when I went to re-connect the 20-pin plug on the video board, but I ran into a problem. Typically, there is one pin missing on the header and a blank in the plug, so you can’t insert it backwards, but in this case, there was not and I had not paid any attention to the orientation of the plug when I’d removed it. Being mindful that if I put the plug on the wrong way, I could damage something, I had a closer look at the PCB and the plug. Luckily, on closer inspection, it was obvious which way the plug went on. The PCB was marked +3.3V at one end of the header, and the 20-pin plug had two red wires at one end. The other end had two holes with no wires in them. So clearly, the end of the plug with the two red wires went to the end of the header that was marked +3.3V on the PCB. Because of the missing wires, it seems that no damage would have occurred if it was reversed anyway, it just wouldn’t have worked. Before permanently attaching the back, I gave the unit a quick test to make sure that it was working. On connecting it up and turning on the switch, I could see the splash screen very faintly, indicating that the backlighting was not operating. I then realised that one of the plugs for the backlighting that I had just re-connected had come out, so I plugged it back in and tried again. This time, the screen came up Australia’s electronics magazine brightly, indicating that the unit was now working. I turned it off and disconnected the plugpack and replaced the 12 screws that secure the unit together, as well as refitting the stand. I could now return the unit to use again after a successful repair. My wife and I both noticed that the display was now a much better colour than it had been previously. I concluded that as the old capacitor was failing, that the voltage for the backlighting must have dropped, therefore resulting in a duller than normal backlight and therefore a slightly washedout picture. The replacement cost of a brand new unit equivalent to this one is over $100, so for 45 cents and a bit of time, this unit was saved from the scrap heap and will live on in its second life. A Suzuki Vitara and its discharging battery S. Z., of Queanbeyan, NSW had the maddening experience of not being able to track down the source of an intermittent fault. Most of us know what that’s like; it seems that the problem will occur any time except for when you are trying to track down its cause! He found it in the end, although it took a great deal of luck… After a long period of being very kind to batteries (some lasting many, many years), my Suzuki Vitara recently started killing them. It began on the morning of the Australia Day long weekend. We were about to leave for a big trip to Morton National Park to tackle Monkey Gum Fire Tail when the car refused to start. The battery was dead flat. That’s never happened before. At the time, I surmised it was just siliconchip.com.au because I had been “showing off” the newly installed winch to the missus the night before, and maybe I’d used up more charge than I’d thought. I managed to charge it up enough to start it, but just to be sure, I bought a new battery that morning and installed it. The trip was a success, although it was tough on the vehicle. Minor body damage will remain forever as a reminder to never tackle that track again. A few days later, when I tried to start the car for the commute to work, the new battery was again dead flat. The battery was also quite warm to the touch. The charger refused even to try charging the new battery. Luckily, I’d kept the old one, and it was on charge. I put the old battery back in and it started the car easily. I thought that I’d simply been sold a dud battery. When I took it to the place I got it, they declared that it had a shorted cell and replaced it for me, although I didn’t put it in the car straight away. The very next morning when I attempted to start the car, it was again dead. The battery was again warm to the touch. This time it had ejected a lot of electrolyte into the engine bay too! I now thought that the car might have a massive “phantom load” that was utterly discharging the battery overnight. Over the years, I’ve added a couple of extra power feeds directly from the battery terminals, including one for radio equipment and one for the new winch. As the winch was the latest change I had made, I suspected it might have caused this problem. Just to be safe, I disconnected everything that wasn’t essential to running the car. I removed the now-dead old battery and put the second new battery in and drove to work – late and somewhat confused. During my lunch break, I started looking for this phantom load. I used an ammeter to measure the current flowing through the extra power wires I’d installed with the vehicle switched off, but couldn’t find any. I then connected the ammeter between the positive terminal of the battery and the battery connector itself and got a reading of about 35mA. That seemed normal. So I was stumped. Two batteries failed in the same way, yet I couldn’t find any phantom loads. I spent the next couple of days doing further current and resistance measurements siliconchip.com.au while jiggling cables and connectors. I also spent time checking the alternator voltage regulation as maybe it was overcharging batteries and causing damage. I was pretty puzzled all as everything measured as being OK. Maybe I’d just gotten unlucky twice, but I started disconnecting the negative side of the battery terminal every night just to be sure. A week after all this began, I had some spare time but was out of ideas, so had another look under the bonnet. I remembered that the last battery event had spewed acid everywhere, so I decided to hose out the engine bay. It got a good wash, especially near the battery, where most of the acid was. Then I heard the distinct sound of rapidly boiling water, similar to frying. This noise directed me to the fault like a beacon. A single wire, part of a larger wire loom, had been rubbing Australia’s electronics magazine against the metal of the battery holder, probably for years, and had finally scraped through the insulation. This wire is obviously connected to the battery positive terminal and is situated in such a way that the slightest bump or vibration could allow it to short against the grounded frame, or remove the short. So that’s why I couldn’t find it earlier. This would have driven me mad. Being well hidden from view means that I would never have seen the bare wire if the sound hadn’t alerted me. The repair was simple: some selfamalgamating tape for the wire, and an extra physical barrier material wrapped around the entire wire loom. Intermittent faults are the worst, and are particularly soul-destroying when it means you can’t trust something you need to use every day. This time, I was lucky! SC June 2019  67