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SERVICEMAN’S LOG Being a gopher for a day Dave Thompson As a serviceman, I’m hard-wired to do most of the maintenance/ installation jobs around the house myself. It’s just the way things are – otherwise known as the Serviceman’s Curse. So when anything needs doing, I’m the go-to guy. However, if something is preventing me from completing any given chore, such as the requirements for compliance certificates or having actual knowledge of the subject, I (reluctantly) defer the task to a professional. Recently, we decided to get another heat pump installed at our home. We already have two downstairs, one in the office and one in the lounge area; both were installed when we moved in six years ago. The new one was for upstairs, to take the night chill off the bedroom areas during the darkest days of winter and provide some respite from the heat during the summer – at least, that’s the theory. Previously, the only heating in this house was from a few strategically-placed standalone fan heaters and a 30-year-old, inefficient Masport gas fire installed in the downstairs lounge. We knew this because we had been friends with the people who lived here for the past 25 years and had been to many a lunch and dinner here, so we were familiar with the vagaries of heating or cooling the house. Due to the somewhat oddball layout of the place (which 90 Silicon Chip has had rooms and bits added to it since it was first built as a single-story house in 1959), the heating arrangement was insufficient to warm anywhere but the lounge during the cold winters we experience in Christchurch. Even then, it didn’t warm things up very well, and certainly nowhere else in the house. The Masport gas fire was the only permanent heating source, and we already knew that it didn’t quite cut the mustard. So when we bought the place, our priority was replacing the Masport with a modern gas fire and installing other sources of heat; otherwise, we’d be constantly cold. Reusing perfectly good aircons When we moved in, we renovated the downstairs areas and, as part of that, had the two heat pumps installed. Both were reclaimed units. The bigger Daikin unit in our office area was initially installed in our computer repair workshop in the centre of town. Sadly, we were ‘quaked out’ of that space after the big shakes of 2011. That was the biggest non-commercial heat pump we could get at the time and did quite well to heat and cool that large, open-plan workshop. It was more impressive because the building was very prone to temperature extremes; it baked in the summer and froze in the winter, typical of commercial premises built here in the 1970s. When we finally had to leave that place (employees wading through liquefaction on a daily basis is not congruent with a happy work environment), we removed everything that we could take with us. That meant the heat pump, the alarm system, the compressed-air supply and any other plant we’d spent a small fortune on installing there. While I could have removed the heat pump myself, I had no idea what I was doing. Given that releasing refrigerant into the atmosphere is illegal, we thought it prudent to get someone in who knew what they were doing. How they capture the gasses, I don’t know. Editor’s Note: they usually use a pump to extract it into a cylinder for recycling and, ultimately, reuse. In all fairness, they could have just cut the pipes and bled the gas out, and we’d never have known, but either way, we ended up with the unit safely stowed away and ready to be used again. This heat pump sat in storage for about five years until we finally found a use for it when we moved into our current home. The second heat pump we had installed in the lounge downstairs (to supplement the existing gas fire) was also Australia's electronics magazine siliconchip.com.au but the pandemic came along and scuppered his plans once again. Can’t help but help out a quake casualty. We’d purchased it on a local auction site after the original owner salvaged it from his quake-damaged house. He had only installed it four months before the quake that ruined his house, and like us, he was loath to leave it behind, even though he had no immediate use for it. After moving into a new house with such systems already installed, he decided to sell it. As it was identical to another Daikin unit we’d installed and enjoyed in our previous house, we snapped it up when it appeared on the auction site. We got it for a fraction of its retail value, so we considered it a bargain. It was still in as-new condition and has given us faithful service ever since. Nudged into action by a cold snap Fast-forward six years, and after a particularly cold snap, we decided it was time to install another heat pump upstairs. Due to events in the meantime, we couldn’t use the original installers/removers. Instead, we hired a guy whom a builder friend of mine recommended. He was apparently very experienced with this type of work. As a know-nothing-about-aircon serviceman, all I could see were potential problems. Firstly, where to put the indoor and outdoor units; secondly, how to run the pipes and wiring required, especially to the downstairs compressor unit. To resolve these dilemmas, I decided to let the professional handle them. He is 15 years older than me (and I turned 60 the other day), and to still be active and doing this work is a testament to his character. I’ve actually done some low-level repair work for him over the years, mainly when he had a compressor PCB with a blown fan-motor fuse; all the fuses on those seem to be soldered in. When a fan motor goes (which I’ve written about before), it often takes the fuse as well. Replacing the motor is easy enough, but the rest of it is dead until the PCB fuse is replaced. You’d think they put in a socketed fuse, but no, they’d rather you buy a $600 replacement board. The guy confided in me that he has tried to retire a few times; the first time, he had trained someone who was all ready to buy his tools, van and plant, but that person got ill and couldn’t do it, so my guy had to carry on to fulfil obligations. Then he again decided enough was enough, siliconchip.com.au Anyway, he rocked up with a shiny new Mitsubishi heat pump. As I’m not the kind of person to sit around and do nothing while others work, I offered to help however I could. This is an interesting dilemma for a serviceman; do you like others looking on as you work? I get the odd customer who rocks up to my workshop unannounced and asks if they can wait and watch while I fix their computer. Usually, the answer is no, not only because I might not be able to get onto it straight away (despite their expectations that I drop everything else) but also because my workshop is small and has no room for people to hang around. I don’t care about revealing any trade secrets (I don’t have any; anything I do can be found on the Internet with even a rudimentary search). For me, it is more about not having someone hovering over my shoulder, possibly interfering with what I’m doing. I find jobs take twice as long if I have to answer a lot of questions from a curious onlooker. It’s even worse when I go to do something, and they claim: “I’ve already done that, and it didn’t work”. Explaining that I have my own methods and sequence of troubleshooting eats up on-job time, which they’d then likely complain about me charging them for anyway! In this case, I was happy just to be a gopher, tool collector, spare pair of hands (or eyes), coffee-maker or anything that might make his work a little easier. He was happy for me to hang around, and I made sure to never get in the way or interrupt his chain of thought, unless he wanted me to. For the first hour or so, we looked at prospective places to fit the units. The landing on the first floor was the obvious choice, but with so many doors leading off it, finding a suitable wall with enough free space to hang the indoor unit narrowed down the options considerably. It stood to reason that if we put the unit on one wall, we’d find a spot for the outside unit on the same side. Either way, it meant running the two insulated pipes required to connect the two units together through one of the rooms, the roof space, and down through the exterior walls or fascia to the ground outside. Then there’s the wiring to consider as well. All up, we had two choices, on opposite sides of the landing hallway, with neither being ideal. At this point, I felt like just flagging the whole idea because it just seemed to keep getting harder. To be an Items Covered This Month • • • Being a gopher for a day (installing a heat pump) “Blown” tail lights on box trailer Acer Aspire laptop repair 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 Australia's electronics magazine September 2022  91 Experience pays off installer, you’d have to have so much knowledge of how to traverse walls, roof spaces, cladding, insulation and other barriers, plus have the tools to do any of those things. No wonder tradies’ vans are so stuffed with different tools and fixings! Routing power and pipes Once we’d decided where the components would go, we had to work out how to get power to each unit. We didn’t have to run power between the two (though that is always possible); different circuits can feed the indoor and outdoor units. For upstairs, there was a nearby mains socket – he would piggyback off that to run the indoor unit. The compressor outside is a bit different – it has to be switched there, usually with one of those large, waterproofed on/off switches inline with the power feed. As the outdoor unit was going to sit outside the laundry, it made sense to take a feed from the washing machine circuit, which was just through the brick wall. The connecting insulated copper pipes (one for liquid, the other for gas) would run along the wall through a spare room on the other side of the indoor unit, then into the roof space, then down through the barge-board and the outside of the brick wall before ending up at the compressor. It would all be encased in a nice plastic conduit where visible and would end up looking quite sharp, even along the spare room wall. A drain is also needed to pipe away water condensate from either unit. Outdoors, that usually just means a drip tray or pipe leading to a garden, but the indoor unit must have a proper overflow pipe fitted into a suitable drain, running it down along with the insulated piping where feasible. Wow! That’s a lot of work to do. Given the number of different structural materials the installer would have to go through – plasterboard, concrete, fibreboard, brick, timber and even tiles, so many different tools are needed. I quickly gained a new appreciation and respect for the guys who do this kind of work all day! I was getting tired just thinking about it. Thank goodness he didn’t have to get under the house. He was getting a bit old for that sort of thing, so it would likely have been me crawling around under there, and that isn’t my favourite activity! 92 Silicon Chip The whole installation only took five hours, which amazed me. We had some guys install pre-built cabinets into our kitchen the week previously, and it took four guys three days. Even then, they didn’t finish it right off. They did an amazing job, though, and as a long-time woodworker and one-time furniture-maker, I also offered my services as a gopher at that time. They politely declined that offer, so I let them get on with it. They were quite disorganised, though, especially compared to the heat pump installer. He had several flexible tool bags, all set out with the specific tools he would need for certain phases of the installation. On the rare occasion that he didn’t have the right tool to hand, he knew exactly where the tool would be in his van, and I would fetch it while he worked on something else. It was a real privilege to be able to watch him work, especially as he seemed to know just what to do without having to think about it for ages (like I would have had to). He was methodical and didn’t waste time on anything but the task at hand. He also used a few tools I had seen but had never seen used, especially the pipe-related ones. He had a very nice pair of Vise-Grip branded wire strippers that he used to prepare the wiring. I tried them out and liked them a lot; I have several pairs of different types of strippers, but these ones worked remarkably well, even on thinner wiring. As a bonus, he very generously gave them to me because he had two identical pairs, and he kept the newer set. Tool score! Also quite intriguing was the pipe drying/evacuation process. He had a small vacuum pump with a couple of gauges mounted to it, and once the pipes had been flared and connected at both ends, he joined this into the system (via a purpose-made valve at the compressor end) and ran it for about 25 minutes. He explained this was to completely evacuate the pipes and dry out any condensation that might have gathered in them, and by noting if the readings on the gauges held firm, he’d know if the system was air-tight. I’d never seen that done before; I had assumed from what I’d picked up over the years that the installer ‘charged’ the systems with refrigerant from a tank they carried once it was all hooked up. However, these days the compressors come from the factory with the refrigerant pre-charged, so all the installer has to do is connect the pipework and open the valves once it is dried and evacuated. While all that was going on, I helped with the wiring, which required drilling a few holes through the walls and routing new cables to the existing power points. Fortunately, we reconfigured the main switchboard when we renovated this place just before we moved in. I made a map of which fuses ran which circuits then, so I knew straight away which breaker I had to pull to isolate the plugs we worked on. This map has come in extremely handy over the years; it meant that my wife could still work remotely from the office without us having to shut the whole kaboodle down. After everything was properly crimped and connected and the guy checked it, I buttoned it all back up. The only things left were to clean up, put batteries in the remote and test it. 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When I picked it up from the dealer, I arranged for them to fit the official Skoda tow pack, which came with a removable snap-in tow hitch and a connector that swung down from behind the rear bumper. Unlike the Hayman Reese kit, the Skoda one didn’t require cutting out a section of the bumper to pass the towbar tongue through. It also came with the bonus of having some smarts in it to know when you’d hooked a trailer up to it so it would automatically disable the rear parking sensors and collision avoidance systems – Simply Clevertm! Also unlike the Hayman Reese kit, however, the Skoda came with a European-style 13-pin round trailer connector. Thus, a 13-pin round to 7-pin rectangular adaptor was required to interface with the trailer. All appeared fine until the first time we needed to transport some green waste to the local tip. We hooked the trailer up to the Skoda and loaded it with pruned branches, grass clippings and leaves from the garden, then set off down the street. A couple of hundred metres down the road, the dashboard suddenly lit up with several warnings – “left turn lamp in trailer blown”, “right turn lamp in trailer blown”, “left brake light in trailer blown”, “right brake light in trailer blown”. We pulled over the car and checked the lamps in the trailer, but both the indicators and brake lights appeared to operate fine when we tested them. We got back in the car and proceeded further down the road, but the warnings on the dashboard persisted and wouldn’t reset, even after pulling over again, turning off the ignition and restarting the car. Satisfied that the trailer was safe to tow with a full set of operational lights, despite what the car was telling us, we completed our journey to the tip, dumped the gardening waste and returned home. Once back in the driveway, I contemplated the possibility that my nice, shiny new car was faulty, issuing false-­ positive warnings about the trailer lamps. A return trip to the dealer for a warranty repair wasn’t something I was looking forward to for a near-new vehicle. 94 Silicon Chip However, as it was the weekend and I only needed to tow the trailer once in a blue moon, I decided to sit on the problem for a bit. The car appeared to drive perfectly OK when the trailer wasn’t connected, so it wasn’t like I was stranded with no transport. I decided to look at the 13-pin to 7-pin adaptor that came with the car. The 13-pin connector end couldn’t be opened up as it appeared to be a sealed unit, but the 7-pin connector could be. With the help of the internet, I was able to deduce the standard pinout of a Euro 13-pin connector. I was then able to use the multimeter to verify the continuity of the relevant pins through the 7-pin connector. While the Euro standard trailer plug includes several functions that the Australian one doesn’t have (independent left/right tail lamps, switched 12V supplies and fog lamps, for example). Everything else appeared OK and lined up with the necessary signals required to make my trailer lamps illuminate. Once again, I hooked the trailer up to the Skoda and verified that all the lamps worked fine, but still, the car complained that the bulbs were blown. So what gives? At this stage, I was now willing to give the car the benefit of the doubt – it was new and Simply Clevertm, after all. Maybe I had some kind of obscure wiring fault in the trailer. I unhitched the trailer and popped the covers off the tail lamps. Everything seemed relatively clean for a 15-year old trailer, the wiring was nice and tidy, and the bulbs were all OK, even when temporarily hooked up to a 12V supply. When the indicators on the car were engaged, I could measure the pulsing 12V in the lamp sockets with the meter. On a whim, I plugged the trailer connector onto the car but left the trailer itself uncoupled from the tow ball, just resting on the ground. Not surprisingly, the dashboard still insisted that the bulbs were all out, but this time when I got out of the car to check if they were illuminated, none of the lamps were working! Like Dave Thompson, I decided to go right back to basics and did a full continuity check on the trailer socket through to the lamps. It took a fair bit of time to run a 3m wire around the trailer to all the measurement points without assistance. Australia's electronics magazine siliconchip.com.au Still, I eventually completed ‘belling out’ the trailer wiring and finally found the culprit – an open ground connection on the trailer plug. But why were the lamps working when the trailer was hitched up, and then not working when unhitched? Then the penny dropped. The ground return connection on the trailer plug is wired directly to the metalwork of the trailer, as are the negative sides of all the lamps. But with the ground wire in the plug open-circuit, as soon as the trailer is hitched up to the car, the ground for the lamp circuits is completed through the towbar to the vehicle body and back to the battery. And because the Skoda uses the trailer connector to monitor the integrity of the trailer bulbs, the returning bulb supervision current was being diverted through the car bodywork instead of back through the ground return pin on the trailer connector. The loss of the return supervision current fooled the car into assuming that all the bulbs were faulty, despite them all working correctly. To test my theory, I temporarily wired a dedicated ground wire from the trailer ground pin to the left indicator lamp. Not only was I now greeted with a blinking indicator, but the car suddenly announced that the left indicator bulb was OK. Re-running a new ground wire from the plug to the frame corrected this problem, and the Simply Clevertm Skoda finally admitted that all the bulbs were there. This kind of sneaky wiring fault would have gone unnoticed on the old Magna, as it did not have any lamp supervision circuitry. As long as the trailer remained hitched to the tow ball, the ground would have been connected through the bodywork, and the lamps would have all functioned correctly. Acer Aspire laptop repair B. P., of Dundathu, Qld is a prolific repairer, and this time, he has turned his attention to giving an old laptop a new lease on life... I have an old Acer Aspire 4315 laptop in very good condition for being 13 years old. I’d been working on others since I got that one, but I thought it was time to check it out. It originally had a single-core 1.86GHz Celeron CPU, 512MB of RAM, and an 80GB hard disk. It would have been underpowered and slow even when new. It came to me with no hard drive and no RAM, so I fitted two 2GB PC-2 RAM modules and switched it on. It behaved erratically, sometimes starting up, sometimes not. I got it to start up reliably by swapping the RAM for a different brand. I’ve previously encountered this problem, but this is the first time I’ve had it happen with a laptop. Because I’m using salvaged hardware, my first step is usually to run MemTest86+ to check the RAM, as I’ve found that some salvaged RAM can be faulty and cause all sorts of problems. When I booted from the MemTest CD, the laptop froze with a screen showing a pattern of squares with random characters in them. On rebooting, the same thing happened. I thought it might be a GPU problem, but the BIOS screen displayed correctly. I decided to fit an 80GB hard drive and try to install a ‘light’ version of Linux, as I’d previously done that for other old laptops with success. I initially tried Linux Mint, but it came up with a missing file error, so I tried Lubuntu. siliconchip.com.au Australia's electronics magazine September 2022  95 The Acer Aspire laptop, and a look at its BIOS (basic input/output system) screen. The installation proceeded to where I had to specify the locality, then it froze. I tried rebooting, but it froze again at precisely the same place. I wondered if the laptop was overheating, as I have encountered that previously and then found that the heatsink fins were blocked up with lint. With this particular laptop, the heatsink and fan are accessible by removing one of the back panels without completely dismantling the laptop, as is the case with most laptops. After removing the heatsink and fan, I could see that they were spotless and then I remembered that I had cleaned them when I’d first set this laptop aside for later testing. Seeing that I had easy access to the CPU, I thought I would try to upgrade it. I’ve dismantled a lot of old, broken and incomplete laptops that were beyond repair, so I have quite a collection of Intel CPUs available. I found six CPUs that would fit the PPGA478 socket. But just because a CPU will fit a socket does not necessarily mean that the CPU will work in the motherboard, as the chipset may not support it. I’ve encountered this a couple of times when attempting to upgrade a laptop, but I would see what happened. I had several ranging between 1.6GHz and 2GHz, so I picked the dual-core 2GHz CPU, fitted it in the socket, then refitted the heatsink and fan. The laptop started up, so I hit F2 and checked the BIOS screen. It now said that the CPU was a dual-core Intel CPU at 2GHz. Success. Sometimes, even if a CPU is partially supported, it will run at the correct speed, but the BIOS will not fully recognise it. Even with a BIOS upgrade, it still may show 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. 96 Silicon Chip up as an unidentified CPU at whatever speed. In this case, the CPU was fully supported by this motherboard. With the CPU upgraded, I started suspecting that this motherboard may not support 4GB of RAM, so I took one 2GB module out and reran MemTest86+. This time, the RAM tested as good. I decided to continue installing Lubuntu Linux, and this time it was successful, so my suspicion proved correct. Because this motherboard supports dual-channel RAM, I swapped out the single 2GB module for two 1GB modules, and I ran MemTest86+ again to verify that the RAM was good, which it was. A check of the specifications of this laptop online confirmed that it does only support 2GB of RAM. It was now time to have a good look at Lubuntu Linux. It has been many years since I last looked at Linux, and back then, Linux was quite difficult and technical to use. I was pretty impressed with what I found. It’s really easy to use and quite similar to Windows XP in many respects. It comes with many applications and has very good support and a large range of applications that can be installed. It came standard with Firefox and Abiword, which was a good start. I looked through the online list of applications available, and I installed Chrome browser, LibreOffice and several other applications. Then I checked that the hard drive and fully set up, Lubuntu had used under 10GB of space. Remarkable. The other impressive thing about these ‘light’ versions of Linux is their support for older hardware, particularly the touchpad on earlier laptops. So far, I have found that Linux supports the two-finger scrolling or one-finger side-­ scrolling features on the touchpads of all the older laptops that I’ve installed it on. This is in contrast to Windows 10, which often does not fully support touchpads on older laptops. It’s often difficult, if not impossible, to find a compatible driver that allows the full use of the scrolling feature of the touchpads on earlier laptops when running Windows 10. So now there’s a way to put those old XP and Vista era laptops and PCs to use instead of tossing them into the scrap heap because they are too old to run later versions of Windows. There are a wide variety of Linux versions available online, and unlike Windows, they are free. SC Australia's electronics magazine siliconchip.com.au