My computer died again.
The computer in question is toastball. That’s the one that currently lives at the Shiny Devices workshop, over on Coliseum Way, and serves the web site, and runs the robots and so on. Why yes, the Shiny Devices web site is served by the very same computer that controls the machines that makes the devices that are available for sale on the Shiny Devices web site.
Or it was, at least. Those of you who have been paying attention will already have noticed that shinydevices.com is up right now, and has been up this whole time, with nary so much as a momentary glitch. That’s because this started out as scheduled downtime. My landlord (Rod) left a note in my mailbox [which is not illegal, by the way — these are different mailboxes from the one the USPS delivers to], from PG&E, about how they were going to be cutting the power sometime between 9 p.m. on Friday and 6 a.m. Saturday, for several entire blocks around Coliseum Way and High St, in order to “install new equipment.” So I switched the DNS over to OFB earlier in the week (I’ve been keeping automatic nightly backups there since forever), and shut everything down on Friday in an orderly way. But when I came back on Saturday, toastball refused to power on. Sad!
I’ve pretty much torn the machine apart now, and my guess is that it needs a new power supply. Either that or new RAM (yeah right) or a new CPU (seems unlikely) or a new motherboard (depressingly probable). But oftentimes, when a toastball dies, it seems to be the power supply.
I have a wild theory now, actually, about why that might be. I’ve been using an uninterruptible power supply — a battery backup power supply for my computer, basically — ever since we had those rolling blackouts back in 2000 or whenever that was. Possibly even before then. Anyway, I can’t help but wonder whether the UPS might be cranking power in the form of a nasty sharp square wave, rather than the nice rounded sine wave PG&E delivers. Could be it only does it when it’s running on battery power. But my theory is that the power supply is desperately trying to smooth out the high frequency nastiness and round off the corners of the squares, and that the resulting stress is reducing its life expectancy.
I’m kind of tempted to investigate this theory by hooking a scope up to the battery-backed outlet in the UPS and see what the waveform looks like. But that wouldn’t be very safe — I don’t have the right kind of equipment in the workshop for dealing with high voltages. It isn’t that the measuring devices won’t go that high; in fact the garden-variety multimeter I’ve been using will measure 600 volts or more, no problem. But you’re not supposed to just stick the little probes in the wall socket and measure the voltage that comes out, because that would be a dangerous and stupid thing to do.
You know, I have a funny story about that, actually.
Some of you will have heard this story before. This is the one about the beautiful apartment that Jessica and I are renting, with its expansive windows overlooking Lake Merritt and its gorgeous non-conductive hardwood floors.
At some point Jessica went down the Oakland public library to find out more about the building we lived in. (Thanks Jessica!) They ushered her into this special room where they keep all of these old maps and Thomas Guides and property records and original plans filed with the fire marshall — all this great stuff! And she discovered that our building was built around 1920, as a 2-unit dwelling, by an unmarried woman named Louise Graff, who was sufficiently well-to-do to build a building and own a car. Louise herself lived in one of the units. She must have kept on building, because by 1925, there were 3 units, and as I write this in 2010, there are 5. Our back bedroom is a few inches higher and has different floors and was clearly added on later. My point is that it’s a beautiful apartment, but it’s had time and opportunity to accumulate a few quirks.
Now, as a computer person who had lived in a couple of older apartment before, usually with a mixture of 2-prong outlets and 3-prong outlets, some of which were not actually hooked up to power, I was glad when I saw that this place had 3-prong outlets everywhere, and that the correct lights lit up on my little 3-light outlet tester when I tried them. Not that it would have influenced our decision much — we’d fallen in love with the view and the floors — but it’s always good to know about these things before moving in.
About a month after we moved in, I flew down to Burbank and drove back in a rented SUV with a brand new fully automated pick-and-place machine in the back, which I temporarily set up in the back bedroom (thanks Marc and Blake!), along with the toastball of that era (the Shuttle SN41G2), so as to reverse-engineer the serial protocol that the horrific Windows control software that came with it was using. [This was also perfectly legal, as I understand it, even though I don’t think our apartment is zoned for light manufacturing; Shiny Devices was not yet open for business, and I wasn’t manufacturing anything back there.]
Most people have never seen or heard of a pick-and-place machine. It’s a type of industrial robot that picks up unbelievably tiny surface-mounted electronic parts [think sand grains] with a tiny little robotic vacuum nozzle and places them on circuit boards that have been pre-smeared with solder paste, usually with a laser-cut stainless steel stencil. Then you run the boards through an oven (usually the kind with a conveyor belt, so you don’t have to open and close it) that melts the paste — a mixture of powdered tin, a bit of copper, a smidge of silver if you’re not too cheap, plus the nasty liquid chemical solvent equivalents of whatever it is that gives Velveeta that smooth creamy consistency in the microwave — and turns it into solid metal connections between the chips and the board, which you then shove into an injection-molded plastic case and wrap up in child-suffocation-warning-adorned plastic film and a glossy pre-printed cardstock box and ship off to Best Buy by the full truckload. That’s tradition, anyway. Shiny Devices is a little bit different.
In order to place the parts accurately, most pick-and-place machines have one or more video cameras connected to powerful computers that use clever machine-vision pattern-matching algorithms to place each part in exactly the correct position and orientation. Mine came with a fancy PCI card with six video inputs (this particular robot only has 4 cameras) and a 3.5″ disk (remember those?) with a license key on it for the terrible proprietary Windows-only device driver that knows how to talk to the PCI card. (I had already explained to the nice folks who made me the robot that I would be providing my own computer.) There was no way that card was going to fit inside toastball’s stylish but cramped Shuttle case, so I borrowed an old hulking Dell from my brother Marc (thanks Marc!) and installed the PCI card and the factory-provided Windows-based robot control software on it for long enough to make sure that everything worked, with toastball as man-in-the-middle monitoring communications between the software and the robot.
Remember how I said the robot has 4 cameras? Three of those are miniature black-and-white video cameras that put out a regular TV signal (NTSC). The fourth, amusingly, is an ordinary Sony digital camcorder, complete with the original glossy pre-printed cardstock box, that attaches to a standard camera mount on the robot frame. I even bought it a little Sony digital video cassette as a present, just so that it would quit whining about not having one. It has a regular TV out, which I’d connected to the 6-input PCI card, but (being a digital camcorder and all) it also has a digital output, which uses a connector that Sony calls iLink and IEEE calls IEEE 1394 and Apple calls FireWire, or DV when it’s being used for video. As it happened, toastball had a FireWire port already, and when I downloaded dvgrab and got the appropriate cable and plugged it in, everything worked great — so well, in fact, that I ended up purchasing an NTSC-to-DV converter box and a computer-controlled video switcher box to hook up the other three cameras. Which meant that toastball would only be able to see one NTSC camera at a time, but that was OK.
Now, a very interesting and unexpected thing happened the first time I connected the video cable between the video switcher (which was plugged in to the three cameras on the robot) and the video converter (which was connected to toastball’s FireWire port). There was a loud noise! And sparks! And smoke! And toastball’s screen went blank! Yikes!
Well of course I unplugged the cable as fast as I could, and when I’d recovered my composure a bit I assessed the damage. The video converter appeared to be dead. toastball refused to power up. The robot, video switcher, cameras, and everything else seemed to be just fine, thank goodness.
So I dialed the customer service number for the company that made the video converter, and I explained to them that I’d just bought their product, and I sort of outlined to them what had happened the first time I’d tried to used it. The fellow who took my call asked me a couple of basic questions, then explained what had undoubtedly happened. The video converter was indeed fried, as was my computer, but it wasn’t strictly the video converter’s fault. Possibly I had inserted the FireWire connector backwards. (It’s an idiot-proof connector — one side is rounded, the other side has square corners — but I can imagine someone managing to force it in backwards if they were sufficiently motivated.) More likely, my computer’s FireWire card (the motherboard, in this case) was shoddy in some way. The fellow went on to explain that their policy was to allow their customers to make this mistake exactly once, but that I should try to be more careful next time. I decided to bite my tongue. He was offering to replace the dead video converter, after all, which was what I wanted.
The new converter arrived soon after, postage paid and exactly as promised, as did the new Shuttle XPC power supply I’d bought online to see if I could resurrect toastball. In the meantime I’d transplanted its hard drive soul into Marc’s old computer, where it was a bit disoriented but managing well enough.
Replacing the power supply wasn’t enough this time, as it turned out, which meant I’d probably need a new motherboard, which meant I’d probably need a new computer, as SN41G2 motherboards were already hard to come by and you’d have to completely disassemble everything and it was so cramped in there that it hardly seemed worth it to go to all that trouble to resurrect what was really quite an obsolete computer. So I decided to shop for a new toastball.
In the meantime, I figured I’d try the new video converter with Marc’s computer, to make sure it worked. I admit to feeling a bit of trepidation when I connected the video cable, which turned out to be justified when the sparks and smoke came out and the screen went blank again.
Now I had two dead computers! (Sorry Marc!)
Well, of course I felt pretty silly! So I resolved to figure out exactly what the heck was going on here before connecting any more video cables to anything.
The whole situation was extremely puzzling! The thing about video cables is that, in principle, they carry only relatively tiny electrical signals back and forth. Certainly not enough to make fireworks! Not normally, anyway.
What about the FireWire cable? Well, according to Wikipedia, the fellow on the phone had a good point there: FireWire cables are actually set up to deliver quite a bit of power, in addition to information. In fact this video converter was being powered directly from the FireWire cable.
But when I plugged the FireWire cable between the video converter and my freshly-assembled computer (toastball), everthing seemed to be fine: the little power light lit up, and there were no sparks or smoke or explosions or anything. It was only when I had connected the video cable that something had gone wrong. Clearly, there was a lot of power flowing through that cable for some reason.
I’d been reading a lot about electronics recently, perhaps because I was going into the electronics business, and one of the things I’d been reading was Tim William’s excellent book, The Circuit Designer’s Companion, which I highly recommend. The very first thing that he talks about in this book is grounding — how important it is, and how easy it is to get wrong, even though it seems like such a simple, basic thing.
You can think of electricity as being a bit like water flowing through a pipe. Electricity is to water as voltage is to water pressure: just as differences in pressure between point A and point B will cause water to try to flow through a pipe between them, differences in voltage are what cause electricity to flow. If I pick up a piece of pipe that’s open on both ends and drop it in a bucket of water, the water won’t spontaneously start flowing through the pipe, because there’s no difference in pressure. This is true whether the bucket is sitting on the surface of the moon or whether it’s at the bottom of the ocean. The absolute pressure doesn’t matter; only the differences. It’s the same way with voltage. When people talk about “zero volts” (or “ground”), what they’re really talking about is the arbitrary reference voltage that they’re measuring every other voltage in the system against.
The point that Tim Williams makes in the very first chapter of his book is that, if you’re going to assume that ground is ground and has the same voltage everywhere in your circuit, you’d better take steps to make sure that stays true. He gives a few examples, one of which involves a workbench in an electronics lab he used to work in where the ground prong in the electrical outlet unexpectedly turned out to have a voltage that was something like 50 volts off from ground in the rest of the lab. As long as you were making all of your measurements relative to that particular ground, everything looked fine — and in fact it was fine. But if you were to plug something in to that lab bench and try to make a measurement with a scope that was plugged in elsewhere…. Well, 50 volts is starting to be a lot of volts, you know? If part of your body were the only thing standing between two things that were 50 volts apart — I mean, it wouldn’t kill you or anything, probably, but you would definitely notice.
I guess that anecdote must have stuck in my mind, because I started thinking: Gosh, you know, the robot is plugged into that outlet over on the far side of the room, and toastball is plugged into this outlet over on this side of the room. What if one of these outlets were like the one in the story? All of these cables have a bunch of different wires in them, and one of the wires is always ground — it’s the reference voltage that everything else pushes against. Usually everything that’s ground is connected together. So if ground were a bit different on each side of this room, you’d get current flowing through that video cable. Maybe even enough to make sparks. How much would you need for that? A few volts? More? I guess I have no idea.
Anyway, it seemed like an easy enough theory to test. I got a voltmeter, and I got the two things I’d plugged together, and I carefully stuck the little probes onto the little conductors on the connectors to try to measure how much voltage would be trying to leap across them if I were to connect them. (It wouldn’t be able to actually leap across; in order to measure the pressure difference between two points, you have to stop the water from flowing between them. Otherwise the pressure will end up being the same!)
Unfortunately the readings I was getting on the voltmeter were not very helpful. They were usally pretty stable, which was good — if you try to measure the voltage between two things that aren’t electrically connected at all, it tends to sort of drift around randomly within a certain range. And they weren’t quite zero. But they were awfully close. The voltage difference seemed to be hovering right around 0.3 volts. Could you get sparks and smoke from 0.3 volts? I was kinda pretty sure you couldn’t, actually. That’s just not a lot of volts. In fact, 0.3 volts is about exactly the minimum amount you need in order for your average piece of sensitive digital electronics to be able to start to notice that the voltage is different at all.
By now I’d been banging my head against this problem for a couple of days, and was starting to get desperate enough to wonder if maybe I should resort to trying to scrounge up another old computer or two just to be able to do more experiments in order to have some hope of making progress. And then late one night I had a thought.
I always set my voltmeter to measure DC volts, as a matter of habit. What would happen if I turned it to AC instead?
DC is electricity flowing steadily in one direction. AC is electricity flowing back and forth and back and forth, rhythmically, alternating directions — there might be lots of electricity flowing back and forth, but if you total up the net flow, you get zero, or something pretty close. Which turns out to be a lot more efficient, in a lot of cases, for reasons I won’t go into today, even though AC seems a bit more complicated to think about. That’s part of the reason why household current is AC, not DC — unlike the teeny digital circuits I’m used to dealing with, PG&E ships a pretty sizeable amount of power around the state, and the efficiency gains end up being totally worth it.
Here’s a better analogy. Instead of water, say the electricity is people who want to visit a museum. The museum lobby is like a wire, and the museum itself is, I dunno, a rechargeable battery or something. The multimeter is the guard who stands in the lobby with the little clicker to count how many people go past. (Actually that guard is measuring current, not voltage, but in this case they’re proportional. Current is how much electricity or how many people are actually flowing through the doors. There are basically two things that determine how many people come in: the voltage, which is how motivated the people are to go in or out [“OMG, is that the Mona Lisa?”], and the resistance, which is how hard it is to get in or out [“What do you mean, tickets are $400?”]. The factors that get lumped together under “resistance” can be broken down further into things like the cross-section of the wire [number of doors or turnstiles or ticket lines, or the cross-sectional area of the pipe in the water analogy] and what the wire is made of — some metals have higher ticket prices than others, or else they enforce their no-glass-bottles policy by X-raying purses, or they have elevators, or they make everybody wear blindfolds and go through a maze. Or something. I don’t know. What am I, a materials scientist now?)
Now let’s say you’re the museum guard with the little clicker, and your job is to make sure that there are no people left in the museum when it’s closing time. You’re going to want to add 1 to your count when somebody goes in, and subtract 1 when somebody leaves. At the end of the day, the count should be zero. You are measuring DC (net) current (people) averaged out over a certain time scale (one business day). The direction the people/electrons are going (in or out) matters a lot to you in that case.
Next let’s suppose you wanted to measure the people/current by sticking part of your body — your finger, say — into the stream of people, such that they have to go through you to get in or out, and measuring the pain you feel whenever somebody steps on your finger. It turns out that when measuring the flow of people in this way, your finger feels pretty much exactly the same amount of pain whether the people are entering the museum or leaving the museum. Your finger is measuring AC people. This might be a good method to use if you are a masochist who wants a very crude estimate of total ticket sales. Similarly, you could try to make a very rough measurement of the the AC voltage of your electrical outlet by sticking your fingers in there and seeing how much it hurts. Strictly speaking, to estimate voltage, you have to factor in the combined resistance of your finger and of the rest of the lobby in order to deduce how desperate the people must be to either visit or escape from the museum, but that’s probably just some fixed scaling factor that you could lump in to the whole “volts per OW!” conversion.
So the next day I went back to my sketchy setup with the connectors and the voltmeter and I turned the little knob from DC to AC and the number on the meter went from 0.3 to 110. Just like that.
Which brings me back to how I got started on this topic: This particular multimeter is designed in such a way that it can accurately measure voltages of at least 600 volts, and sometimes even 1000 volts, without smoke or sparks or whatever. What it isn’t designed to be able to do is to protect the human being presumed to be holding the meter from those kind of voltages. There are some fairly well-thought-out rules about these things, you know? It sounds a bit confusing at first, but it’s a perfectly sensible distinction to make. What I was doing right then with these fiddly little metal probes was safe for the meter, but it was not especially safe for me. Or for toastball, for that matter.
But wait! It gets sketchier.
Remember that 3-light outlet tester I was talking about? You can find them at almost any hardware store. They’re cheap. There are three lights because there are three prongs on an electrical plug, and if you want to look at the voltage across every possible pair of prongs, there are three pairs. So each light tells you whether there’s a voltage difference between a particular pair of prongs. There are two yellow lights for voltage between hot (110 volts AC) and neutral (0 volts), and between hot (still 110 VAC) and ground (also 0 volts). There’s a red light for voltage between neutral and ground.
Now, you might wonder why an eletrical plug would have two different prongs that are both supposed to have exactly the same voltage, namely 0 volts. Why not just have one prong? And, of course, in older apartments with 2-prong outlets, that’s exactly what you find. The reasoning back then was that it doesn’t really matter which prong is hot (110 V) and which is neutral (0 V); all that matters is that the difference is always 110 V. (The direction in which the electricity is going doesn’t matter either, because this is 110 volts AC, so the direction changes back and forth constantly — 60 times per second, in this case.)
That’s fine reasoning if all you care about is your stuff getting the power it needs, but if you also care about safety, then you also might decide that you want to pay attention to the voltage difference between (say) the metal casing of my toaster or computer or what have you, and the voltage of the person who might be touching that case. If the difference is 0 volts, nothing happens and everyone is happy. But if the difference is large — 110 volts, say — then you will notice, and you will be unhappy. This can happen if, for example, a live wire comes loose inside your appliance and comes into contact with the metal case. It’s pretty rare, but it can happen.
The idea behind the third prong is that that prong is electrically connected directly to ground. There’s a big metal spike or pipe or something sticking deep into planet Earth at a single point underneath the house, and there are all of these wires radiating out from that point to all of the ground prongs in the outlets, keeping them at the same voltage as that patch of the actual literal ground. Which is why it’s called that. There is also an entirely separate network of wires radiating out from that single point to all of the neutral prongs on all of the outlets, and yet another wire connecting that point to the ground wire coming from PG&E.
When you plug in your toaster or computer or other 3-pronged appliance, the metal case of the computer is electrically connected to the 3rd prong, to make sure it has the same voltage you do, assuming that you are standing on the ground, to the extent that it’s possible to ensure that. If a live wire were to come loose inside the toaster, instead of silently electrifying the outside of your toaster, it will get into a fight with the ground wire over what the voltage should be. There will be a huge difference of opinion! Lots of electricity will flow! So much, in fact, that the circuit breaker will trip or the fuse will blow, and you’ll be safe.
Why not just have 2 prongs and connect the outside of the toaster to the neutral wire, instead of having all these redundant 0 volt wires? Well, first there’s the problem that the video converter tech support guy was talking about — polarized plugs are designed to fit only one way, but if you’re motivated enough, you can plug them in backwards. Now the outside of the toaster is connected to
110 V, not 0 V, and you’re in trouble.
The other problem is that, unlike the ground wire, the neutral wire is being used to carry significant amounts of eletricity. When it does that, the voltage rises above 0 — not all the way to 110, usually, but if you’ve ever noticed the lights dimming when the fridge comes on or when you turn on the vacuum, you’ve seen that the voltages of the hot and neutral wires are drifting noticeably closer together. You do not want the AC voltage of the outside of your fridge to rise every time the compressor kicks in! That’s why it needs separate prongs for ground and neutral. This is exactly the sort of problem that Tim Williams talks about in the first chapter of his book, by the way, though the context is a bit different. The point is that it’s always important to ground things correctly! And these things aren’t always immediately obvious. That’s why, when high voltages start to become involved, we have safety rules about these things.
Anyway, whoever did the wiring in this apartment either didn’t know about those rules or didn’t figure they were very important. All those 3-prong outlets? They don’t have separate ground and neutral wires. The wiring in the walls is the older kind, with just 2 conductors: hot and neutral. Each outlet has its own little wire tail that connects the ground prong directly to the neutral prong. Presumably the tail is there solely to fool the 3-light tester, which turns out to be exactly the tool the eletrical inspector from the city usually uses to make sure everything is hooked up correctly. It’s pretty hard to tell the difference unless you set up an elaborate experiment where you draw lots of power and measure the voltage more accurately, or open up the wall and look inside.
Which is fine, mostly. Usually wires don’t spontaneously come loose inside of electrical appliances, and usually appliances don’t draw enough power to bring the neutral wire far enough away from 0 volts to be really dangerous, and if they did, the fuse would still blow. The difference between 2 prongs and 3 is usually a subtle one, and one that people didn’t worry about at all until a few decades ago.
No, the real problem here was that, on one of the outlets in this back bedroom where I had the robot set up, the hot and neutral wires were reversed.
Normally, the 3-light tester would catch this right away. But if you’re tying neutral and ground together right at the outlet, so they both have the same voltage (110 V AC, in this case), the 3-light tester can’t tell anything is wrong. If you look at the instructions that come for the tester, you’ll find some vague disclaimer about how this this is possible, even though it’s usually pretty unlikely to happen by accident.
The other way you’d normally prevent this situation is by the color-coding of the wires inside the wall. The hot wire is black, the neutral wire is white, and the ground wire is usually just a bare metal wire, because it’s always at 0 volts and is just a wire stuck into the ground and it’s about as safe to touch as anything can be.
Back to the story. When I saw the number 110 on the multimeter, I set it down carefully, backed away slowly, thought about it for a long time, and went to fetch my 1-light tester. This is like the 3-light tester, but it just has two prongs and one light. The prongs are on flexible wires, so you can use them on either a 2-prong outlet (which was why I’d bought mine — to check to see if a 2-prong outlet was hooked up to power) or on different pairs holes in a 3-prong outlet. Unlike the multimeter probes, the prongs on the 1-light tester are designed to be relatively safe to stick into an electrical outlet; once you stick it in far enough to make eletrical contact, there’s little or no metal sticking out where you could touch it accidentally, just like with a regular eletrical plug.
I got an extension cord, and I connected my 1-light tester between the ground prong at the bottom of one outlet (the one toastball was plugged into) and the ground prong of the other one (that the robot was plugged into). And it lit up. Exciting!
After doing a bunch of similar experiments, and a few quite different ones, I was starting to get a pretty good picture of what was going on here, and what it might take to fix it. Probably I could just turn off the power, unscrew that outlet, swap the hot and neutral wires, close it back up, and everything would be fine, more or less. It might even be legal for me to do that, for all I know. But there are lots of rules, and I don’t know them, and by now I’m starting to get tired of this thing where I end up doing stupid dangerous things because somebody wasn’t paying attention to the rules. The rules are there for a reason.
So I called up our landlord, and I tried to explain. Our landlord’s name is Joe, and he’s a really nice guy. He works hard to keep the property in good shape. He didn’t really understand what I was going on about. But he agreed to bring in an electrician.
The electrician shows up and asks to see what I think is wrong. I wordlessly repeat my demo with the extension cord and the 1-light tester. The light comes on. “This,” I maintain, “is the problem. The entire metal case of whatever I plug in here gets electrified. If it weren’t for these fine non-conductive wood floors, I might already be dead.” I may have been exaggerating a little bit for dramatic effect. 110 volts won’t usually kill you directly. I bet it could start a pretty good fire, though.
Joe is looking on. He seems pretty nonplussed. The electrician too. I mean, come on! If this stuff were really as dangerous as I seem to be incoherently claiming, wouldn’t it be more obvious than that?
“Hold on,” says the electrician. And he goes back to his truck and grabs a 3-light tester and comes back upstairs and plugs it in to each outlet, and the 2 yellow lights come on, and the red light stays off. “See?” he says. “It’s fine.”
“Yes, actually, I have one of those too,” I begin.
And then we start to have a discussion. And then he stops me to tell me a story. I don’t remember the details anymore, but the story involves a situation in which this same fellow is working on something, in a dark, wet, cramped, unpleasant crawl space, with some exposed pipes, and he isn’t wearing boots, and the ground is wet, and his feet are wet, and at some point he happens to touch one of the pipes, and he gets a nasty shock.
And as he’s telling me this story, I start to realize that the punch line of the story is not, as one might hope, that he stopped what he’d been doing and figured out why the pipes were all eletrified and fixed the problem and made it safe. No! The moral of the story turns out to be that sometimes these things happen, and 110 volts usually won’t kill you, and that’s just the way the world is, and I should really just learn to suck it up.
“I can’t help you,” he concludes.
“Great!” I say. “You say you can’t help me, and I believe you 100%. Now get out of my house!” I think that, anyway. I must have used different words, at the time. Joe is looking a little bit embarassed. Later I wonder if I should have asked that dude to show me his license to practice electricity. I still wonder about that.
Once they’re gone and I’ve calmed down a bit, I go on the Berkeley Parents Network and troll around for recommendations for competent electricians, with a license from the state, and I come up with a list, and I make a few calls. Competent electricians, it turns out, are in demand. They tend to have busy schedules. But I do manage to get in touch with a couple of guys who call themselves Fighting Amish Electrical Services. I explain to them that I’m pretty sure I know what’s wrong, but I want to hire them to come in and check out the wiring at my house, and see what they think. I explain that I’ll be paying them for their time, and maybe Joe will reimburse me and maybe not — I’ve decided that it’s better to ask forgiveness than permission — but either way I want to do whatever I need to do to make sure the house is safe, dammit.
So they come in, and I congratulate them for having an awesome business name, and I show them my little demo, and I try to explain what I think is going on. And they look pretty skeptical, especially when the 3-light tester shows it’s OK, but I’ve agreed to pay them a considerable amount to check things out for an hour or two and they’ve agreed to do it. So they turn off the power and unscrew the outlets — sure enough, they’re not properly grounded, and that’s not right, but it’s nothing to get excited about, either especially in an old house — and they yank and scrape and test with the meter, and pretty soon they’re like, huh, you’re right. This one is backwards. These wires are the wrong color! Yikes!
Some time later, they ask if I know how to get into the attic. They say there’s probably a junction box up there, with the other ends of the wrong-colored wires, and it would be good to fix those before somebody else comes along and gets into trouble. I tell them that I have no idea how to get up there, but I’ll ask Joe. It later turns out that Joe doesn’t know either. I don’t think he wants to know. I think he’s afraid there might be asbestos or something. He told us, when we moved in, that there might be, somewhere, for all he knew, so we should probably assume there was, and not go stirring things up. Sounds like good advice to me.
So the Fighting Amish guys swap the wires and wrap the in appropriately-colored tape as best they can, in all the spots that they can reach without demolishing the house. Then they ask what I want to do about the 3-prong outlets that aren’t really. They explain that they can’t legally leave them like that. (Not the ones in the bedroom, anyway. They quite rightly refuse to speculate about the outlets elsewhere in the apartment, since they haven’t looked at those.) They can either replace them with 2-prong outlets, maybe, or they can disconnect the ground prong and put a little blue sticker on each one that says “NO EQUIPMENT GROUND.” (In theory, they could also come back and demolish the house and put in actual proper wiring in the walls. But not today.) 2-prong outlets are hard to come by these days, but they have lots of stickers. Sure, I say, put stickers. So they do that. By now they’ve been at it for least 2 hours, and they have other appointments and a non-trivial hourly rate, so I let them go.
Once they’re gone, I plug everything back in and, with some trepidation, I connect the video cable for the third time. Nothing explodes. All 4 cameras now work perfectly.
I gladly pay the electricians’ bill when it arrives. They even forward a copy to Joe, along with a more comprehensible and credible explanation than I was able to provide. He apologizes to me by phone that his electrician couldn’t fix the problem, and he reimburses me. Good for him! I offhandedly mention the idea of tearing the entire house apart to redo all the wiring with 3 conductors instead of 2, and we share a nervous little laugh, because the truth is that neither of us especially wants to turn the place into a war zone. I once witnessed a previous landlord make a much less ambitious improvement to some dodgy grounding. Not fun! I sure got some good use out of my UPS at that place, let me tell you.
Meanwhile, back at our Lake Merritt apartment, I got out my extension cord and my 1-light tester, and I checked every single outlet in the apartment to make sure none of the others were wired backwards. Turns out they’re all good. Though there are two in the living room that stay on even when I pull all of the fuses and turn off all of the breakers. (Why yes, this apartment has both.) The oddness with those outlets didn’t really have any practical impact on our lives until quite a bit later. But I’ll have to tell you that story another time. Right now I’ve got to run over to Fry’s to see if a new power supply will resurrect my dead computer….