‘I nearly died after flying thousands of miles to install a power cord for the NSA’ Welcome once again to On Call, The Register's Friday column that shares your terrifying tech support stories. This week, meet a reader we'll Regomize as "Kent" who told us about a job he held in the 1980s, when he worked for a manufacturer of some of the first digital waveform recorders and logic analyzers – vintage kit for …
Had it been an oscilloscope, reconnecting the Earth pin could have caused much spitzensparken the other side of the break-room wall. It was a frequent trick to get a "floating" measurement to extract the earth wire from the plug. You would need to wear gloves to operate the 'scope, though!
To point out that the software was working precisely as spec'ed, but the End User wasn't using it properly.
No, that wasn't in the spec, yes, it would be useful[1], here is an estimate.
[1] note: always "useful" or "an interesting addition" whilst on site, never "so bloody obvious an omission that a blind man could see it, I kept on telling the managers we needed this, but, no, no, it was always far more important that we kept changing the shade of green in the prompts until Sales were happy it matched the letterheading".
They probably didn't get much information about what the problem was, so they needed someone who could check whether it was a software problem and someone who could check whether it was a hardware problem. The problem is eventually deciding to check both of those possibilities rather than getting stuck on one of them.
"They probably didn't get much information about what the problem was, so they needed someone who could check whether it was a software problem and someone who could check whether it was a hardware problem. The problem is eventually deciding to check both of those possibilities rather than getting stuck on one of them."
There could have also been a big order pending for more kit and sending both techs to have a squizz was going to look better to the people signing the approvals for the PO (up until bonehead crashed the car).
I once had a 02:00 call from someone who announced themselves as "Admiral Pacific Fleet" and I caught "costing us a million dollars a day" before I removed the shouting from my ear, until I detected silence (about 45 seconds). I then calmly asked what the symptoms were and was bluntly told "No, someone else will call you!" Less than a minute after he put down the receiver, someone who was much calmer called me, but the answer was still "no we cannot tell you!" OK, so I went back to bed.
This underling had given me an email address (which I recognised) to use to contact them. Over the course of the next day I sent a number of scenarios to this email address each asking if this might show a similar problem. To which I almost immediately received a single word response "NO". Eventually, I received a "YES" about 24 hours after first contact. OK, so I went to bed to cogitate over the issue.
I worked out what was wrong with their configuration of the device (and connected devices) quite quickly, emailed them, but never got a reply. The email asking for a "customer survey" response (sent the next day) bounced!
That would be Hawaii. And, depending on the date, said Admiral may still have had the ambiguously named "Naval Security Group Activity" as part of his responsibility.
They're now called "NSA Hawaii", though the sign says "Navy Communication Site".
/Just finished reading "Joe Rochefort's War", all about listening to the other side's radio messages during WWII in the Pacific.
One place I worked the Company Chairman had a notoriously way with interviews. He insisted on picking up one poor applicant from the station and driving him the 3 miles or so to the office. At the end of the lane he overcooked the corner and ended up in a ditch. He just leapt from the car, grabbed his briefcase and shouted, "we can walk from here". When he got to the office, he handed the keys to the receptionist, and said "My car's in a ditch. Get someone to tow it out please" and proceeded with the interview.....
Personally, I'd rather work for a company with a chairman who might occasionally crash their car with me in it than one that makes me sit through a 'mindfulness' seminar every other month just because someone else had a breakdown. Ironically the aforementioned seminars felt like they were bringing me closer to a breakdown.
I've worked for a company where the boss, and his son, have crashed many times.
His son could not get personal car insurance, so was on the company insurance. Having already written off one car, The insurers were like 'One more writeoff, and we'll refuse to cover you.'
Soooo..after his next crash...the insurers were about to write the car off, and wash their hands of the company, when daddy personally paid for the car to be repaired (WAY more than the value of the car. Chassis straightened in a jig, and everything.) Tested, back on the road. There, not a writeoff. Premium gone up by thousands. Don't care. 3rd party cover only. Don't care.
I'd really rather not be a passenger with them.
In all my working life (more than 50 years) I've never come across anything like this, nor those of the previous commentards, and wouldn't put up with it for a second. The closest I came was back in the late 1960s when I was deeply engrossed in fixing one of the new and exciting colour TVs and the manager breezed in and demanded that I drop everything and post a letter. When I tried to object, he switched the power off. I walked out and never returned.
P.S. The nearest post box collection time was midday, and this was early morning.
"When I tried to object, he switched the power off. I walked out and never returned."
I'm contemplating that for a customer that called up and I met on site to see what was needed since I'd have 10 minutes I could schedule for them while I was in the area that day. We both drove up to the property at the same time and she set the alarm off and it didn't seem to shut off with the code she remembered. She got on the phone with the alarm company and went into full bitch mode telling them to just shut the damn thing off. Not the sort of thing I expect an alarm company is going to do for somebody that's just called in rather than them calling her listed number. I've got this feeling about her. I'll do the job when it's ready, but it will be cash up front. Then again....we'll see.
Very common for datacentre access airlocks to include scales to check you are not leaving with undeclared booty. Always worth checking before you go in so you ensure you have the same toolobox/folders you started with and did not inadvertantly swap with a colleague
Does it? Right now it's borderline... quite literally. It's ok to be racist if the people will non-caucasian features have a foreign passport, but that line is getting thinner and thinner, because they're getting more and more ready to call out US citizens as somehow "foreign".
Senator McCarthy had nothing on this lot....
No security measure is ever foolproof. The best you can do is to keep piling more on until the risk/cost/inconvenience trade-off reaches an appropriate equilibrium.
The problem is that, out of a desire to optimize for cost and/or convenience, we humans tend to underestimate the risk, and so have a tendency to get the equilibrium catastrophically wrong.
Back in the day, when the IRA started sending bombs through the post, someone had the bright idea of issuing the front desk (I hesitate to call them 'sevurity') with metal detectors to scan incoming boxes and packages
They immediately discovered that most of the boxes contained metal and the detectors went into the back of a cupboard, never to be seen again
"Very common for datacentre access airlocks to include scales to check you are not leaving with undeclared booty."
Quite a few years ago when I was working at a certain telco testbed/DC in La Defense I was told the "airlocks" weighed people for security purposes - this was obviously BS as I entered each morning with my laptop bag and left for lunch without said bag and no alarms etc sounded.
"They probably aren't too concerned with you weighing LESS than when you showed up"
Well you could have a very large breakfast before going to the site, at some point while there make use of the toilet.......and then have a certain amount of "spare" weight to carry something out lol
The Brotherton Special Collections at Leeds University Library do that. Some years ago we were looking at some of the C19th manorial rols which are huge but which were very dusty. They weighed a bit less when they were returned because most of the dust had fallen out. They were still doing that wen I was there last week.
Scales:
One thing to try is to bring in a 10 lb/kg weight, that is pretty compact (lead works), Then leave it "behind". It would be interesting when they find out you weigh less than before.
You might even do this with your own body, as it produces waste products (letr your imagination wander here!).
Articles like this really put me in a bad mood when I realise I used to use such "Vintage Kit" as an undergraduate engineer. No wonder my body aches so much, as I'm obviously vintage too.
(In fact I'm so old that I've even seen some of my product designs proudly displayed in museums. Now THAT was a very bad day ...)
So have I.
My first job as a newly minted engineer was working on part of system for the Danish Navy that was to used for tracking ships sailing through Danish waters. At that time the Cold War was very much a thing and the navy officers, I occasionally interacted with, used the phrase "when the ballon goes up" meaning now the Warsaw Pact is coming and they bring a helluva lot of stuff most of which can go BOOM!
The Cold War eventually died down and the system, I had worked on was decommisioned and ended up in the Cold War Museum at Stevnsfortet. If ever get to that museum and take a tour down below, you will enter a room with some big consoles with a large round screen and two smaller screens on each side. That was part of the system, that I worked on - and it is now in a museum.
"My first (proper career) job was with MoD. The whole site is now a museum and a European Heritage site; some of it is an SSI; and some a Scheduled Ancient Monument. I knew I felt old..."
The year I started on my BSEE was the first year the curriculum didn't have any coursework with tubes. I had to learn that on the outside and it's paid better than semiconductor work from time to time. I did some repairs for a local guitar player on an old Fender amp he has and was told he hadn't been able to find anybody within 100 miles that would work on tube gear. It's not something I do officially either, but we got to talking at the hardware store (I think) and I agreed to have a go. Some bad caps, as usual.
Danish Navy job -- Was this in the late 1970's to early 80's? My then employer put me on a team preparing a response to a Danish RFP (Request For Proposal) that sounds very like the system you describe. Scariest moment came when it was my turn to present a chunk of our proposal to the visiting Danes, all in full uniform with at least four stripes if not more, all with sternly chiseled Nordic faces, all apparently taller sitting down than I was standing up, and all glaring at me. Our bid didn't win...
Concerning the "intersection with a huge berm:" Our proposal included a sort of conceptual diagram of the system, showing how one computer acted as fail-over for the other, how they managed to be electrically isolated, and so on. Each computer had its own eighty-megabyte disk drive, "medium-sized" for that era. The diagram labelled each as "80MB" which was easily misread as "BOMB" ...
Probably 25 years ago I went to an exhibit on computers at the Smithsonian. It had the ZX-81, Commodores, Apples, Trash-80s, all that fun stuff... stuff that I remember being cool and new.
I think that's the first time it hit me I really was getting older (now I have no doubt!)
I went with a friend to 'The Kirkaldy Testing Museum' in London which contains devices principally used for testing the mechanical properties of materials (a fascinating place, old fashioned and a bit untidy). Many of the exhibits just seem to remain, located where last used before someone finally switched the lights out. One of the items on display was an instrument for calibrating pressure-measuring devices. The curators were rather disparaging of this simple device (pressure = force (weight)/area) implying that it was aged and a bygone technology; no-one knew how to use it. Rising to its defence, I advised that the dead-weight calibration device was a fundamental machine and very easy to use. In fact we had a modern version in regular use to calibrate precision transducers. The only difference was that ours was clean and in its case; the museum example was exposed, so dirty from accumulated dust/oil and spiders-webs.
I half-hoped they might offer me a job, but all I received was a pitying smile.
Finally managed to visit there last year, after a decade or two of it being closed whenever I was in London. Yes, fascinating and well worth a visit for Commentards. https://www.testingworks.org.uk/
Incidentally, I got the same response when I tried to make a suggestion. But otherwise the hosts were v friendly.
Last Xmas my grandaughter told me that her then boyfirend, a history student, had a vacation assignment writing an essay about the late troubles in N Ireland. That was part of my working life. It does raise the question of how long does it take for the chip wrapper to become history.
"[...] vacation assignment writing an essay about the late troubles in N Ireland. That was part of my working life."
The Troubles weren't part of my personal experience living in Canada, but I certainly remember them on the news.
What hits closer to home for me: as a kid in the 1960s, watching WW2 movies on TV, that conflict seemed like ancient history. But it had ended only a dozen or so years before I was born -- a relative eyeblink, as I now realize.
Something else to think about, for us oldsters: somewhat over 40% of the world's population (including, presumably, many here) are too young to remember life before the World Trade Center attacks; they've known only the post-9/11 dystopia. (Source: PopulationPyramid.net, which is fascinating in its own right.)
Went to an extremely competent, well-run training on data collection at a site which delivers social services to people who use drugs yesterday (mainly so I could better understand the context in which the data I will be playing with got generated). At some point the extremely competent person delivering the training used her own birthdate as an example in a form. Which was 2001. Which caused the 10 or so 50-something heavily tattooed former prison inmates (and my own 50-something self) to burst out laughing because we all instantly felt old. To the trainer's credit she said 'yeah, I know, I young' and just rolled with it. Anyway, I was talking to my spouse about it later and we were marveling that there's now an entire generation out there in the workforce for whom things like 9/11 are ancient history, not lived experience (and I'm writing from the US where 9/11 is still D-Day level importance in the national narrative).
85yr old bird here - i still remember quite clearly going into the bunker in our garden when the WW2 sirens went off in London. I vaguely remember the Yorkshire Dales where I was evacuated to for a while as a 3yrold during the war ! The World Trade Center ? That was yesterday ! I had one full blown career in a health field then my first computer was via mail order from the Tandy people - 1991? - I was already 51 - took a class in Assembler & Cobol coding & spent the next 2 decades+ having the time of my life initially in a mainframe environment, then PC's & java etc - wrote my last lines of code just 3 years ago for a friend's project - now I just boast about how smart I was, when I am not pontificating on some other subject or other ! This brain refuses to go quietly altho it's container is gradually giving up !!! Have fun everybody - don't let AI take away from the most fascinating subject you could wish for !
"bunker in our garden when the WW2 sirens went off"
An Anderson shelter? I've read about those. Very fortunate that the British government had the foresight to develop them before the war broke out.
When I was an apprentice with a large motor manufacturing company in the late sixties and early seventies, one of our most feared postings was to an electrical subsidiary in Belfast during the Troubles. Luckily, I was posted to their equivalent in Enfield, north London, but several of my peers who did go to Belfast told harrowing stories on their return, and one actually committed suicide because of his experiences there.
"It does raise the question of how long does it take for the chip wrapper to become history."
There's a fish'n'chip shop at Beamish Museum. They use coal fired fryers and proper beef dripping (with a "warning" notice for the feint of heart vegans who might think a bag of chips is a "safe" option" :-)) The recently opened "1950's town" might be a bit scarily recent for some of us. Even being born in the '60's, there was far too much in that area that reminded me of my childhood!!
Here in the USA, anything on government land that is over 50 years old is "historic" and you're supposed to leave it be. Including things like rusty old beer cans stuck in a dried up old wash in the middle of nowhere.
This means that rusty old mine dumps full of busted machinery, old mattresses and furniture, and rusty bean/fuel/whatever cans are no longer eyesores full of hazmats, rather they are historic places.
I worked at some of those mine sites over 50 years ago ... Whodathunk my old garbage would be considered "historic".
In other news, more than once while browsing at Weirdstuff Warehouse I ran across a rack or cabinet which I had built for one company or another, now on sale at roughly scrap prices. One example I remember distinctly was a pallet with four cabinets on it, each one jammed full of telco gear (echo cancellers in their shelves, line card shelves with line cards, power supplies and UPSes, ring generators, a Sun pizza box to talk to it all with a couple of dumb terminals to supplement the console, three modem shelves with AJ dial-back modems, patch panels, and various alarms & etc. All with my company stamp on it. Probably $175,000 worth (including the wiring) when I assembled it all and shipped it out not 5 years earlier. And still conveniently plastic wrapped and palletized for your convenience. The kit had obviously never been installed. Even the box full of the paperwork/manuals that came with the kit was still tucked in behind the ring generators, unopened since I had taped it closed. The only change since I had last seen it was a large sign taped to the outside: $250 Takes The Lot!.
The daft thing is that all the individual components were still available off the shelf from the original manufacturer. In fact, they probably STILL are, around 35 years later ... I thought about buying it and parting it out ... And then I realized how long the kludge would be taking up space at my place. Ebay (as "Auction Web") wouldn't exist for a couple years yet ... which was undoubtedly why Weirdstuff was trying to get rid of it en masse.
I had an Uncle who was a electronics service guy for the CIA back in the 1980s. One story he had, on the last leg to the job in some unnamed South East Asian country, his escort opened the bag he was carrying and asked if my uncle "knew how to use this". This was a sub-machine gun.
Posting anonymously for obvious reasons.
of miles to be nearly killed.
Back in my time of <redacted> for the civil service, you only had to fly 10 miles to dangle from a wire and get nearly killed. (among other things)
And what made it worse was the members of her majesties armed forces we worked with got paid more than we did.
"Whats up Boris? you dont want to fly? you were fine down that dark hole in the bottom of ship the other day... apart from the screaming and shouting when we turned the lights out"
The chemical company that I worked for had two large offices about 10 miles apart. Occasionally we would have to go from our office to the other office for meetings, seminars etc. On this particular day we had eight of us in two cars. Me with my Mk2 (it was the 1990s) VW Golf and my boss with his somewhar larger Peugeot 406.
At the end of the seminar (about 3pm) we returned to the car park where four passengers made a beeline for my Golf and squeezed 3 in the back seat plus one in the front. I was somewhat nonplused as Fred's car was considerably larger and more comfortable for passengers than mine.
On asking why everyobne made a dash for my car, I was asked if I had ever been in a car with Fred driving.
No, I replied.
Well if you had, you would understand why none of us wanted to travel with him.
The gentleman in question, despite being an academic of some standing, evidently frightened passengers on a routine basis due to a complete lack of observation and awareness of other road users. I was happy to observe from a distance of about 50 meters in the driving seat of my own car.
There are generally two reasons for an American plug to have an absent ground pin. First it just came off and is stuck in a socket somewhere. Cheap stuff will do that. Second, someone removed it to fit the plug into one of the many sockets in the country that take only a hot and neutral pin. The second one suggests shenanigans of the worst kind given the location.
Incidentally, I've long expected ultra-secure establishments to go to "nothing in, nothing out" procedures where people are expected to leave everything, including outer clothes, in an outer locker room, proceed to an inner room in their skivvies, and then dress for the job. So many places just let the cleaners in and out with whatever they can carry or even put on a cart.
And to parody Douglas Adams, in some NSA location one might expect that "the difference between the amount you eat and the amount you excrete will be surgically removed from your body mass when you leave".
I've never had a ground pin break off in the receptacle. Not saying it can't happen but they are the largest/strongest pin in a NEMA 5 plug.
Most likely they had removed the ground pin at some point because they plugged it into something that lacked one. Hard to imagine the NSA would skimp on their electrical work and install receptacles that lack the ground pin. There was probably some sort of cheap extension cord they'd plugged it into in the past, and someone decided the best way to make it fit was to remove the ground pin.
A nice likeable bloke I used to work with had been positively vetted at a previous role many many years ago in a galaxy far far way. As a result he did any secret work for Her Majesty’s Government that his ex employer was aksed to do. He said he ended up having a new manager due to the old one being pensioned off. A few days later he was sent to a secure location to perform some work. His manager asked where he was going and was told in response I can’t tell you that’s classified I’m afraid. Manager very unhappy asks again and is told, that the man can’t tell him where he’s going, what he’s doing when he gets there, nor who he’s meeting.
Manager is incensed that this is undermining his authority and ability to keep track of his subordinates. His manager tells him that’s tough luck frankly, the work is classified, as is the location, even he doesn’t know where it is. The manager isn’t happy with this reply but has an idea, the expenses sheet. When he submits expenses for the job they’ll be a train ticket and he can see then where the bloke is going. Expenses submitted the manager says ah so the secet location is at Rowley Regis in the West Midlands, that’s where you go is it?
The reply my colleague gave was along the lines of If that’s what you think I can’t stop you from believing that. He told us that to preserve the secret, they would supply a used train ticket to the value of the actual ticket. They wouldn’t tell us where the place was either, nor what work he did there.
>>The reply my colleague gave was along the lines of If that’s what you think I can’t stop you from believing that. He told us that to preserve the secret, they would supply a used train ticket to the value of the actual ticket.
Even that leaks some information as there is a finite set of places with that cost of train ticket.
Well, to be precise, there are a finite number of all train stations, but a smaller set with a given cost of ticket.
Even that leaks some information as there is a finite set of places with that cost of train ticket.
Well, to be precise, there are a finite number of all train stations, but a smaller set with a given cost of ticket.
I don’t know if the original poster is still reading this to further explain when this was or maybe further clarify. I would have thought there was a lot of variables in train ticket pricing if you vary the departure station and the destination station the pricing would be variable for tickets especially if you added in railcard discounts etc. Also we don’t know if it was an exact price match or whether there was wiggle room. I’m really curious now as that would be an interesting way of dealing with a travel expenses and a need for secrecy. If it was during the time of BR and as this was presumably government work, maybe wherever this bloke went had their own ticket machine for this.
The few times I took that kind of job, the client always gave me the travel tickets and hotel booking info in the limo on the way to the airport (and usually a credit card and a few hundred bucks in cash and/or whatever the local currency was at the destination). My company knew what I was doing (they provided the kit), but they had no idea where I would be doing it. I was young, single, and stupid ... and it paid well. Very, very well.
Ostensibly, it was all legal ... but I balked when they told me to leave all my ID at home as I would be provided with alternate passport, driver's license, insurance cards, social security card[0], etc. along with the airline tickets ... I'm not interested in the "spy" game. Far too much room for error.
[0] That should date me ... We actually carried our social security card well into the 80s. Why, I'm not sure, it was just a done thing.
I've come across both issues with dispiriting frequency in my working career. Probably twice as many missing pins as pins stuck in sockets.
Extra scary when it's a live or neutral pin missing! Once had to have the facility sparky remove a power pin from a socket, as the electricity had to be shut off first and I had no way of knowing what was on the same circuit.
The NSA which is supposed to keep the country safe from terrorists, a place full of very smart people that break codes, hack into Governments and run super computers, could not troubleshoot a faulty power cord? Thousands of dollars spent on a service call replacing a ~$10 cord, Do they fly people in to help employees open doors at work or how to put one foot in front of the other to get to the office?!
It's not that surprising. Often, things are considered a specific person's responsibility, and it is sent to them to do rather than trying to find someone who can manage it. The machine is doing the wrong thing, so complain to the machine's support contract. If you try to fix it, that's a waste of time because we have a paid support contract, so you're spending time doing something someone else can do. There's some logic in that, because if the software was wrong, it probably would either require the manufacturer to do something altogether or could be solvable by someone local but not without introducing some other risks. The best workplaces are staffed by people who understand how much you can solve before it is a good idea to call in someone else. Bad ones either stick to a policy without thinking or don't understand what's realistic and what isn't.
The real question should be if an org such as the NSA has electrical and electronics experts, who was the "qualified technician" who removed (and why) or broke off the earth pin and why didn't they associate that change with the change in behaviour of the machine? Maybe someone "lied" to hide their incompetence when they broke off the pin. That happens all the time and I'm sure we have all had users who have no idea how the "accident" happened.
It's not just TLA techs who do this ... I;ve seen it all over the place. Here's an old post of mine from 2009, originally titled "That's just the switch, they do that!" ...
The scene: Old house in Mountain View, converted to Vet clinic.
The time: Late 1999.
The job: Convert the Vet's database from non-Y2K compliant PSI/Idexx on HP/UX to Cornerstone on Win98 (I know, I know, but that was what the Vet wanted).
Considering that Cornerstone included the database conversion in the cost of the 8 hour staff training session, my job was basically setting up the Windows boxes, installing software, and pulling wire. Easy. In fact, I did the complete network setup back in my lab, so all I had to do was make space for the computers, printers, label makers etc., plug it all in, and turn it on.
Unfortunately, the house was built in the post-war building boom, and originally had 2 prong plugs for mains power. Some had been converted to three prong, but not all. I had to convert the six locations where the Vet wanted the computers installed. Three new breakers, pull some wire ... Again, pretty easy.
Day of install, the Saturday afternoon before the Sunday the Cornerstone rep was to hold the staff training session. The Vet wanted me to plug a scanner into her personal machine. The floppies that came with the scanner didn't come with Win98 compatible drivers, so I used the new-fangled V.92 modem to dial into my ISP ... But the connection speed reported as 2400 baud instead of the expected 56K (or so). I broke the connection, redialed, same result. And again. Now, I had already used the modem from my lab, just to verify it worked, so I knew it wasn't my hardware ... I picked up the phone. Line noise. 60hz line noise, to be precise.
I turned to the Vet and asked how long the phones had been buzzing ... she brightly answered that "That's just the switch, they do that!" ... WTF? After further questioning, it turned out that instead of having six phone lines coming in, she had a small switch with six extensions. It was installed when she took over the practice about a decade earlier. (You can probably see where this is going ...).
She lead me to a storage and washing machine room in the back, and pointed at the wall. Hanging there was a dusty, cobweb covered, slightly sad looking $TELCO supplied switch. It had a three-prong cord ... plugged into a two prong socket. The $TELCO tech who did the install had cut the ground pin off the power cord to fit the availabe mains power. I asked her to go get me a cordless 'phone and grabbed a wire coathanger. With phone to ear, I grounded the case of the switch to the cold water pipe with the coathanger ... No more AC hum.
I explained the situation to her, and she went ballistic. After she calmed down a little, I asked if she wanted me to call $TELCO for her. (I could have put a new cord on it myself, and put in another 3-prong socket, but if you touch $TELCO gear, they will refuse to fix it if anything goes wrong in the future.) On further questioning, she allowed as to how in the last decade she had had techs out half a dozen times or so to service her telephones, including what sounded like a firmware upgrade to the switch itself.
Long and short of it, we had a $TELCO tech out 45 minutes after I hung up the phone.
"Thousands of dollars spent on a service call replacing a ~$10 cord"
Sometimes it's not until you are throwing everything at the wall that something finally sticks. The unit fired up and was doing things, just not doing them well enough to be useful. Plenty of things will work just fine without grounding as it's often only there for safety. It would seem in this unit, it was important for shielding too.
Over time, I've learned to look under desks for dangling cables that might get kicked and cause troubles. One of the reasons everything under my desks is tidied away. I can just imagine the tech under the desk/bench checking that the lead is firmly plugged in, removes it in case a cycle freshens up the contacts and then spots the missing pin. This is why I like it when things are properly burnt. I can smell there is a problem and once the cover is off, I can point at all of the bits of the capacitor that blew up and find where it came from (power supply, usually). Intermittent and nebulous faults drive me crazy.
Sounds familiar. Many decades ago, I was involved in the certification testing of an avionics system. Which involved the communication of data between several components using the ARINC 429 format. As we were pressed for time and budget, commercial bus readers capable of reading several dozen data labels simultaneously were not available to our project. Being a young, naive engineer, I offered to work with our lab and build one in house. It was to be based on an IBM PC clone, built on an ISA development card and driven by software I was to write. To make things simple, I spec'd the same ARINC chipset that the system vendor used as well as the same signal conditioning I/O circuitry. So each avionics box would think it was talking to its neigbor. I just handed our techs the vendor schematic, circled the applicable section and said "Make it like this."
We put the whole thing together and it didn't work. I told the techs to hook up an oscilloscope and see what was travelling between boxes. It turned out that what reached our ARINC UART chip through the I/O circuitry was +/- 1 Volt. ARINC specified a minimum of +/- 5 Volts. A bit of napkin scribbling revealed that one component in the vendor's circuit was off by a factor of 10, in effect creating a voltage divider. My bad for blindly copying someone else's work without checking. But the component in our reader was changed and: sucess. Total time wasted: about an hour.
I went back to my boss and reported the good news. And suggested that the vendor might want to check their design. A few days later, boss came back with the news. The vendor had completed the original h/w design under a very strict division of labor rule. Hardware people were not to write software (test stubs) and software people were not to fiddle with hardware (oscilloscopes). They had been beating their communications bus problems over the head for months, hiring expensive software consultants. With hardware that, due to organizational rules, was basically just "thrown over the wall" from their electronics people.
back at the beginning of my career I was a software diagnostician for a mainframe manufacturer, when a customer encountered a serious fault that could not be diagnosed remotely I'd often be sent out to site to meet a hardware engineer. I'd be looking at any software dumps / diagnostic logs while he was running hardware tests.
Often issues would show up as lost comms between the CPU and a device (disk or comms controller) that was a head start for the hardware engineer but sometimes I could get down as far as identifying the device being used for the transaction, saving hours of hardware diagnostic tests nd getting the customer back on the air.
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