Hands On
There is no substitute for standing next to the box and prodding it.
Sometimes you're the one on the phone, and other times you're the one that issued the cry for help. Welcome to a story from the On Call archive where a Register reader turns the tables and claims the glory. Today's tale comes from "Rob" and is set in the 1980s, at a City insurance company. As was common in those days, the IBM …
And as I always tell my engineers, whilst analysing data and test results is fine, the two most powerful troubleshooting tools you possess are located just above and on either side of your nose. There is no finer piece of problem solving equipment than the mk 1 eyeball.
Many a time I've had customers who escalated an issue after "working on it" for weeks without actually going anywhere near the tool, where it has been solved almost immediately by walking up to the tool, looking inside and spotting the bit that's hanging off or in pieces on the floor...
One problem is assuming the problem is in a particular place. Once fixated it is difficult to change one's mind.
When I was in college we had an intermittent fault on an IO controller (back in the days of room sized boxes). It would come and go and shaking the big wire wrapped door would cause failures. The field engineer was puzzled. I finally located the problem by passing my hand over the wire wrap pins until it caused the problem. refining my touch I located a single pin that was causing the problem. At which point the field engineer looked closer and discovered a small piece of bare wire resting on the pin. The automatic wire wrap machines would occasionally drop inch-long pieces of wire on the boards/doors they were wirewrapping.
Another time (in product development) I designed a board to drive a laser printer. It used a UART to communicate with the printer. Everything seemed to work except the test group claimed I was sending an extra character at the end of printing. So I added microcode to log every character sent and received from the printer and there was no extra character.
The product development people had hooked up a terminal to monitor communications and this terminal showed an extra character. I watched a test run and noticed that the character was sent at the end of printing when my program terminated. Then I discovered that the UART sent a runt character when it was reset. So I reprogrammed to send an "all mark" character before resetting and the extra character disappeared.
When troubleshooting it is difficult to eliminate biases. One must often start from the beginning and reverify the symptoms etc.and start debugging again. Since we were in research there was no guarantee that the hardware or software worked so we had to debug both in parallel.
"One problem is assuming the problem is in a particular place. Once fixated it is difficult to change one's mind."
Oh yes. A couple of weeks back we got the insurance - Domestic and General- backed repairer round to sort out the constant warning beep in our fridge ( normally indicates the door left ajar).
He told us that the panel at the back of the freezer section was frosted up ( there was a thin ridge of ice). That we needed to empty the fridge/freezer and defrost for 24hrs with its doors open.
This didn't make much sense, so I contacted the manufacturer (Liebherr)- they have a very good helpline as it happens.
They asked me a few questions,including "Have you had any power cuts recently?. Which we had.
They told me to switch off the fridge, then switch off the plug. leave for an hour then put it back on.
When I came to do this I discovered the electronic touch control panel was frozen ( not in the icy sense). Something the visiting "engineer" had failed to even look at.
So in time honoured fashion I turned the freezer off at the mains, then back on again. Control panel then functioned. So I turned off the fridge as directed, (might as well do it all properly) and mains again. After an hour or so turned it all back on, and yes. Problem solved.And no need to find a temporary home for a freezer full of food.
Worked with a lady tech some years back, Friday afternoon pissing down outside & waiting for our early Friday afternoon finish.
The smell of cooking resistor suddenly filled the air & she busied herself with checking every bodies test bench for the culprit (Unsuccessfully), then returned to her own bench in some puzzlement just as the glowing resistor on her unit under test finally burnt itself out.
Sitting in the lunch room many years ago, when all of a sudden one of the techs head went back and he sniffed the air. Without a word being said suddenly all the techs stopped and sniffed the air, got up and ran for their benches.
Will never forget the smell of burning tantalum capacitors.
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> ...checking everybody's test bench for the culprit ....then returned to her own bench ....just as the glowing resistor on her unit under test finally burnt itself out.
My father found a plug, no cord, in a wall outlet. In a fit of pique, he blamed my mother. Who denied it, then wisely shut-up.
A week later he goes to use his soldering iron, and the plug is missing.
Bizarrely, next week is their 70th wedding anniversary, still living together.
When diagnosing the faulty caps used during the early 2000s on motherboards from a certain manufacturer, first sign was an acrid smell,a pop followed by a ping as the metal case from the leaking capacitor left its earthly shackle and flew for freedom until it hit the side of the PC case.
The Nose 0.7a (still in early testing found a eggy smell near some UPS banks. Using TouchTemp(tm), we found that the UPS batteries were cooking rather nicely.
Never had to use taste yet at work, apart from experiments back in school with a PP9 battery. Tangy, with hints of citrous.
I possess no less than eight hammers in various weights, and despite three full sets of ordinary spanners, four adjustables ('shifters' in local parlance). One of these shifters, the largest, has magical properties in that its mere presence induces faults to disappear. Indeed, it was used to cure a leak on a friend's central heating system and when it left the premises, the leak returned. I couldn't afford to be without this invaluable piece of equipment so my friend photocopied it and put the print next to his boiler: the leak stopped.
Some years later, that friend had moved house but I know that photocopy remained, continuing to offer protection.
I believe the scientific term is Percussive Maintainance
The art ney Science behind knowing exactly where to hit the thing and how hard to bring it effortlessly back to life in the desired configuration.
The best example of which displayed by a certain Arthur Herbert Fonzarelli
Back in that sort of time-frame our lab was next to the workshop & I got on well with one of the technicians who had previously worked at Shorts (aircraft). He told me of some job he'd had specified which required a hole to be drilled in timber and then opened out to square. He waited until the boffin had left the room and then got a square section steel rod and a hammer...
Wrong. I’m a school science tech. We have a plethora of bits of wire with plastic handled banana plugs on the ends, occasionally a crocodile clip which may be insulation shrouded is there.
The banana plugs when the kids pull the wires out of them are often reluctant to come apart. The metal slides up into and out of the plastic. I have a big geology hammer which must be used fairly delicately. I have yet had to grasp the end of the hammer and WHACK! something. Judicious taps suffice.
I only started mid April. The kids are told to pull the plug not the wire but bare wires with separate plugs keep coming back. I have started to hold the metal part in chunky pliers enabling maximum torque to be applied to the wire fixing screw.
Amazing the appreciation you can get for putting some plugs on some wires. They were without a regular technician for 2 years before I applied. I’m handy with a multimeter and a soldering iron as well as pliers and screwdrivers. So I do that stuff in addition to making up solutions and doing dissections for the non biologists.
Music think I’m wonderful too. 4 amps fixed and counting. A drum kit and a keyboard too.
Ex CDT teacher here. Less practical teachers/departments were (almost) always grateful for repairs as they knew that there was no chance of getting broken kit replaced. The ones who weren’t grateful, or took me or my colleagues for granted, only got one repair before being effectively blacklisted.
We weren't allowed to bring hammers aboard the aircraft. So we called it Brogan Maintenance. For any of you old time SAC folks out there, you remember this. B-52 and ARC-34? There ya go.
Open the panel, toe kick the UHF radio and it stopped cycling and locked in on freq. Usually traced after flight to a loose tube in the Oscillator Multiplier.
An 18" adjustable spud wrench is well over 200 quid. I'll use the handle as a lever, there's no way I'm using the head as a hammer.
I've never seen a 'miner's wrench' style tool with a decent adjustable wrench end. But if they exist I'd still worry that you're going to cause impact-related wear on the adjustable part.
"Assuming prodding may involve the use of hammers. Large adjustable spanners may be substituted if you find yourself suddenly hammerless."
Hehe, Photonicinduction comes to mind! "Where's my 'amma?"
Then when he's "fixed" it, "I popped it!!"
He's a crazy awesome Londoner who does crazy experiments with VERY high voltages! I recommend giving his YouTube channel a watch!
Which drives my better half completely bonkers, since I'm know far and wide in the family as the one who will wander off and start poking at things. She gets shouty at me, though in a quiet voice in case the crowd around us figures out what I'm doing near (but not to!) the "Big Red Button" I've noticed and starting wondering about. Heh.
Eh, the inscrutable error messages throw one off, and can completely hose your debugging tree.
For example, I filled my FJR-1300 up at the gas station, then it wouldn't start, with an error number that meant "bad crank position sensor" so I was like "well that's fucked then" and called for a tow truck, which basically put an end to getting anything done for the day.
Turned out to be a bad starter relay, and the computer went "well I fired the relay, and it's supposedly cranking, but I'm not seeing anything, so it's gotta be a bad crank position sensor!"
If I'd **known** it was a bad relay, it would have been a simple matter of push starting it. But with the stupid and incorrect error message, I was thrown off course.
Ive done same. my Supra used to crank for a lot longer than i thought was necessary before starting , and after trying a variety of things , new crank position sensor included , it turned out the starter was worn and was cranking too slowly!
Not slowly enough for me to notice , but slowly enough to confuse the ecu!
This. I've had an ECU fail due to a rather odd chain of circumstances:
- ecu turns on low speed fan
- relay flips over
- dropper resistor has failed, so no fan
- ecu gets it's 'fan running' signal from the relay, not the fan...
- ecu thinks fan is running but engine is a little warm, continues to drive the fan relay
- thin wire driving that relay isn't really rated for that continuous current and melts a bit into an adjacent wire
- volts get where they shouldn't in the ecu
- $$$...
And all because the designer saved a couple of bucks by not looking at the other side of the dropper resistor.
Do it in second gear, not first.
Start by pushing up to a fast walking pace, then SLOWLY ease the clutch out while continuing to push to keep the speed up.
And be prepared to engage the clutch quickly when the engine catches .... or you'll find yourself being dragged down the road!
I've tried to push start my ex-step-mum in a Cortina. After I stopped cos it hadn't started and I was bright red and covered in sweat, she then 'innocently' asks if I want her to take the hand brake off!!!!!
That was when I really learned that blonde hair was a sign of all the brightness leaking out! ----->
One night, a few years ago, a fireworks display was being set up at my rugby club. The lads doing the work has left the lights of the van on so they could see what they were doing, but this ended up flattening the battery. Wasn't room to push it forward so we tried bump starting it in reverse, coming very close to success. After a few tries, we had enough space to successfully do it going forwards.
Rugby players 1, diesel transit 0.
I always push start my diesel Renault in reverse (which, unfortunately happened a lot this past year, until the mechanic realized the starter motor was shot). Much easier than doing it in second gear, going forward. At one point I mastered the technique of letting it roll back off the tiny inclination in my driveway, and that was enough to get it running. The worst part was getting it to pass the bump in the garage door.
Icon because it's Friday and I feel nerdy -->
On the level or a down slope I could bump start my Reliant Regal in 2nd gear by opening the door, sticking one leg out, paddling it along vigorously, and letting go of the clutch when it was rolling. Happy days. When it got a hole in a piston I bought a used engine for a tenner and swapped them myself.
We once had one in the Botany department as a loaner at the start of Autumn term. Several of us were taking Archaeology freshers out round some of the local sites (my branch of botany was closely related to archaeology). The lead car was a Spitfire, I was in the middle, trying to keep it in sight and at the same time let the minibus behind keep me in site. The road holding was fine but we did end the day with not much left on the brake pads.
Used to have an Austin A30.
Dead battery for nearly a couple of years.
Used to wind it up with a cranking handle to start it - no problems.
Only bought a new battery to impress then girlfriend now love of my life.
Back when you got a manual and set of tools with the vehicle!
RIP old car.
Myself and 2 friends tried to push start 1000cc BMW boxer twin. We failed miserably as the rear wheel locked up no matter which gear we used - turned out it needs the starter motor to operate the decompressors on that model.
It can only be started with a fully charged battery
Cause of Flatus Battus? Headlight stays on unless you take the key out.....
:-)
In the past I've had two Subarus throw up apparent engine problems. Checking the error log shows ECU cannot regulate engine speed. Problem - regular enough to be Googlable - faulty switch reporting it's in neutral when it isn't so ECU tries to set idle speed. Current car has so far had two wheel sensors replaced. Vehicles are increasingly dependent on electronics and the sensors that feed them; those sensors need to be a good deal more reliable than they are, otherwise it's GIGO.
Back when I was a teenager & still (mostly) obeyed my dad, he ordered me to help him troubleshoot his Subaru Impreza. Because he was so much smarter than any Chilton or Hayne repair manual, he refused to read them to determine what the error message the car computer was giving. "I can fix it myself." was the words of doom that now let me know the speaker is an idiot & that I should immediately turn & run like hell.
Cue an entire weekend spent struggling to undo bolts that dad can't reach, hoisting the engine out of the chassis, power washing the entire thing "to check it for leaks" (Sigh), and poking, prodding, & "testing" every last nanometer he could get at with a screwdriver. To no avail. Sunday afternoon rolls up & it's still not working. Since mom had to be at work Monday morning (dad worked the night shift so had another few hours for his own needs), we were forced to reattach everything, remount it in the chassis, & try to undo whatever further idiocies he'd introduced.
We're a few bolt turns from done when he "accidentally" breaks a small plastic thingamajig. He gives me money, a 3x5 card with the item description, & the part number from the side of the item. He sends me the six blocks away to the auto parts store with *explicit* instructions to buy *exactly* that part & no other. So off I go to do as asked.
The guy at the counter reads the 3x5 card I hand him, gets a scrunchy face of concentration, & asks "Did you check $OtherPart first? It's usually what goes wrong first and results in this part (waggles the card) to fail."
I have no idea, it's not like dad to explain anything (nor that anything he thinks matches with anything from *this* plane of reality), so all I can do is shrug & reply "I honestly have no clue. We've just spent since late night Friday until now tearing it apart, testing everything, and that part broke while we were putting it back together just now. I'm to get that, bring it back, so we can finish the job & hope the car runs again."
He gets me the part, I pay for it, & he asks me to ask my dad to come see him after we're done. I thank him & head back home.
Dad installs the part, tries the engine, & it still refuses to start. He's about at the end of his rope, a situation which is not improved when I relay the parts man's request. Dad drags me to the store & has me point out the employee. Said employee makes it easy by waving at me & calling out "Hey! You're back!"
They talk, dad feeding the man a line of obvious bullshit, the man not buying it, and dad trying to defend his "testing" regime. When the parts man asks about the part to check that tended to fail first, my dad swears up & down that he had tested it & found it fine. Except I knew for a fact that he'd done nothing of the sort. How? Because *I* was the hands that had to hold all the test equipment while he applied the test probes, and we never touched the part in question.
Dad says he'll go remove the indicated part, bring it in, & prove to the man that it's still good. Back home we go, I help him remove said part, & back we trudge to the store.
Dad presents the part & says "There. See? Perfectly fine!"
The parts man washes the part, dries it completely, turns it over, & shows the BIG FUCKING CRACK down the bottom that disproves my dad's claims.
Dad grumbles, pays for a new part, and we go back home with dad muttering & mumbling a blue streak the entire way.
Install the replacement part, go to start the engine, & it purs to life just as neat as you please.
I later went back to the store & asked the man how long the fix would have taken had my dad bothered to RTFM. "About ten minutes to loosen a few bits in the way, five minutes to swap the part, and another fifteen to put it all back together. If it took an entire hour, you were doing it wrong." I thanked him & let *MOM* know of that fact.
"You mean your idiot of a father wasted TWO DAYS when the whole thing would have taken under an HOUR?" *Me nods* "I'll kill that dumb fuck!" *Cough*
I have *always* accepted when something is beyond my knowledge & should be entrusted to a professional. If there's a manual, I'll RTFM to make sure I know WTF I'm supposed to be doing. But if even RTFM doesn't enlighten me, I'll pay a pro to do it right the first time. This is the exact opposite of dad whom refused to RTFM, insisted he could fix it, and would usually wind up having to take $Item in to be *actually* fixed by a pro anyway (and for much more, since dad introduced further things in need of fixing).
TL;DR: Always Read The Fine Manual, it can save you days of headache, massive amounts of money, and a metric fuckton of embarrassment when someone points out that you are, in fact, an idiot for not having RTFM in the first place. =-)p
My family and I were on holiday in Wales when the Cortina's engine repeatedly cut out. It would run for about 40 miles and then stop. Read the Haynes Manual, which told me the fault was caused by dirt in the carb float bowl, so stripped the carb down and cleaned everything out, put it all back together and - Vroom. 40 miles later, stopped again, so repeated the carb cleanout, and set off again. Eventually reached camping site and engine stopped again, blocking the site entrance. Whole family piles out and shamefacedly push dead Cortina into site. Decided dirt must be coming from fuel tank to repeatedly block carb, so spent first real day of holiday removing and cleaning tank, blowing out fuel lines, and cleaning carb (again). First test run was circumnavigation of island, car stops dead within 100 yards of site entrance after (you guessed it) 40 miles. Gave up in disgust and walked back to site for a cuppa, leaving car on verge. About an hour later, went to try engine, starts first time and drives into site. Curiouser and curiouser, so circumnavigated island again, 40 miles later,engine stops dead, but this time inside campsite. Whilst cranking engine, Father in Law has head under bonnet and notices that there is a spark running down outside of the coil insulator. I borrow (ie steal) the coil from his Escort and fit it to my car, which immediately starts and runs perfectly. Went to local garage and bought new coil, which solves problem perfectly. Seems that when the coil got hot, it failed internally and produced sparks where it shouldn't, but the cooling off period while I fettled the carb, etc, rectified the fault, which would then reappear when the coil reached operating temperature, about 40 miles later. I have never trusted Haynes manuals since, I always check other information sources before following Haynes' instructions.
Back in the dawn of time I sat in a friend's Viva for a drive from Merrie Coventry to St Ives, Cornwall. He had just rebuilt the front end & suspension having smashed it to hellenbach driving over a pile of hardened asphalt.
Every 50 miles or so it overheated. He insisted he had cleaned the radiator before refitting it, and was totally befuddled by the classic symptom of a blocked radiator.
We drove most of the way with the heater on full blast - in July. The glue holding the soles onto his girlfriend's shoes melted.
After a couple of days of intra-Cornwall boiling over he decided to remove the radiator and several other essential bits of the engine, like the cylinder head (in the campsite - the things you do when you are young, eh?).
While he was tidling around with various bits of the engine he had dismantled in the hope of discovering The Problem I suddenly thought to ask what he had cleaned out the radiator with.
"Ariel".
There then followed some class four Words of Power from yours truly and the instruction to go and buy a bottle of vinegar. Over the course of the next hour, using the vinegar as a rinsing agent, we managed to dislodge several large clots of washing powder that were impeding the proper operation of the forward heat exchanger, after which it functioned more or less as it was supposed to.
Then Chief Engineer Dimwit kicked over the rocker box and scattered the head bolts into long grass, requiring him to walk a search pattern in bare feet to find them again.
It was all quite depressing.
Post of the week SS !
Seen this type of thing happen over the last 40 years but not so brilliantly described. Never been a fan of the Imprezza ( I was an avid RS2000 fan and had a few, standard and stupidly modified.) Easy to work on and a lot of fun but admittedly well before the electronic stuff that took over and made cars very boring.
Have a very good weekend Sir.
have *always* accepted when something is beyond my knowledge & should be entrusted to a professional.
Which, since this is largely an IT site- so rather more appropriate, is how I've been with IT.
Having started as an amateur and drifted into semi-pro work because in education until at least the early 90s there was seldom any kind of outside support. I did my best to keep up with the tech. But once there was a limited amount of support I was able to call upon this is exactly what I did. As soon as I met a problem that I knew I didn't fully understand- or that was a risk of causing worse problems I handed it over to a specialist. I had my own job, with the IT just being an add-on and there was no way I could have justified the time for training to keep up this stuff to a pro standard. And I was not prepared to bodge jobs that were beyond my skills.
My dad could fix almost anything by looking at it, but never *ever* read "the destructions".
This precipitated the event one Xmas Day after he had (finally) bought a betamax recorder "so mum could record her programs".
He looks at the remote. He looks at the front of the recorder. Cue 10 minute rant about designing controls on a remote that weren't on the body of the recorder (high-quality chartered engineer ranting I might add).
I spent about a minute in the manual, walked over to the machine which was almost melting under the fiery blaze of said rant and flipped open the drop-down door to reveal the "missing" controls.
Cue five more minutes of harrumphing.
I think we had either the same, or very similar models. My dad did the same "look at the remote, look at the machine, & start bitching" routine. I was standing at the machine, noticed the flip down panel, flipped it, & revealed all the hidden controls. Cue dad going appoplectic about "idiots that couldn't design their way out of a toilet paper tube".
As always, my mom & I sat down to RTFM while dad fiddled with the remote & getting nowhere. Mom asks to see the remote, dad nearly throws it at her, at which point she follows the instructions & programs the machine to record her show. Dad screams "How did you do that? I've been trying to get it to DO anything for over an hour!"
Mom backhanded him with the manual, left the remote on the coffee table, & told me she was going out for a walk. I decided to join her rather than stay home & listen to dad rant & rave.
I remember that machine rather fondly, I got to use the frame-by-frame feature to admire Princess Leia in her chainmail bikini. Hubba hubba rawr! =-)p
I, as many of my generation, never got much of a chance to connect with my father at any level beyond the occasional mechanical/repair job. Back when I was 10, he got the hobby of purchasing old Lambrettas and Vespas, "restoring"* them and then selling them to youngsters for a profit. He promised to give me a cut of the selling price if I helped him with the engines, given i used to spend my summer afternoons at the moto shop of my friend's father. 35 years after I'm still waiting for my cut, but I still remember vividly how I had to undo the engines in a hurry to fit the many small parts my father deemed unnecessary while assembling them... All before my dad tried to start them, with unexpected -for him- consequences...
*"Restoring" because his enthusiasm and accuracy usually faded pretty fast. All of the projects started as an 80s Overhaulin' episode and ended as a 90s demolition derby...
> For example, I filled my FJR-1300 up at the gas station, then it wouldn't start, with an error number that meant "bad crank position sensor"
I had a similar issue with my FJR: filled up, went to pay, came back and it wouldn't start - completely dead. Ten minutes of faffing later I realised I had knocked the kill switch somehow!
In my defence I'd never done it before in 8 years of ownership.
"Hopefully in search of a hot beverage and morning sustenance."
Where I worked in the 80s the hot beverage would have been a crap cup of coffee (or powdered tea) from a vending machine but the canteen provided mid-morning sustenance in the form of fried egg rolls which I took full advantage of.
<heads off to kitchen to fry eggs...>
"When you have eliminated all which is impossible, then whatever remains, however improbable, must be the truth."
I've never liked that expression. It barely makes any sense.
When you've eliminated the impossible , theres a boatload of possible things remaining so you're no nearer your answer.
I usually start my diagnostic procedures by writing off the impossible from the start.
Maybe if I eliminate everything thats possible I'll go back and start looking at the impossible , but usually the answer presents itself well before all possible solutions have been exhausted.
Its no surprise Dirk Gently was a fan of this method , given his predilection for creative invoicing.
Sherlock Holme's detective skills are entirely Conan Doyle managing to carry you away with the story. If you ever stop and think about the stories, they're ridiculous. You can think of a dozen prosaic explanations for something Holmes claims has just one that, 'however implausible', must be the truth. (Or the entire story is hinged on something only Holmes knows, and not the reader.)
The character is brilliant, and they're excellent works of fiction. As detective stories, though, they're pretty weak, because the reader can't try and solve the crime.
But eliminating something means that you have discovered it to be impossible. You don’t eliminate it whilst it is still possible! And that’s what Holmes meant. Once you have assessed all the possibilities and eliminated all the ones that turn out not to be possible then the one that is left must be the answer even if it feels unlikely.
So this is a common misconception, how can you eliminate the impossible unless you know the thing is impossible.
E.G. Mr red could not have killed Mr white as he was seen by ten people a hours drive from the murder and never left their sight.
While Mr Green was ten minutes down the road and while he also had an alibi he disappeared from sight for 20-30 mins.
Therefore once you have eliminated the possibility of Mr red being the killer it is obvious that is Mr green.
Assuming there were only ever two suspects of course my dear Watson.
Er...
You start with things that are possible. As you rule them out, they become impossible for various reasons. (E.g. is it possible the switch is broken? No, it's been tested, it's impossible that's the problem.)
Because you're not an idiot, you're testing things and ruling them out in rough order of plausibility. Having rendered all the likely things 'impossible', you're left with the implausible.
True, taken at literal face value, that quote is meaningless. Works better if the last part is "however improbable [you think it is]..."
I've always taken it to poke fun at our human ability to think that something is so unlikely that is effectively impossible, when our estimate of that improbability is totally out of whack because of a gap in our knowledge. A humble reminder that no matter how well you think you know something, nature can always surprise you.
A serious tip:
Find the USB logo on the plug and put it in with the logo facing you. Should be right >90% of the time, as the USB 2.0 spec says:
Receptacles should be oriented to allow the Icon on the plug to be visible during the mating process.
Even better tip: If you have a USB device that doesn't have a USB logo (like a thumbdrive) or it's black-on-black (thank you Mr. Desiato), mark it! Sharpie works well on light-colored items; Wite-Out / Tipp-Ex works well on dark items.
@albegadeep - Oh, I see your misconception, um, make that misconceptions:
"Should be right >90% of the time, as the USB 2.0 spec says:" - Do you think the underpaid workers in that sweatshop have read the USB 2.0 spec?
"Receptacles should be oriented to allow the Icon on the plug to be visible during the mating process." - Which direction is "facing" me when I'm reaching behind a box for a vertically-oriented socket? In a dark corner?
I haven't seen a bottle of Tipp-Ex containing liquid for years!
"When you have eliminated all which is impossible, then whatever remains, however improbable, must be the truth."
One of the big problems in the IT world is that people suck at eliminating the *probable* (power switch turned off, power cord unplugged, Ethernet cable unplugged) and jump to working on the implausible.
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Many years ago I worked in a city centre ale house which had one of the new fangled CD jukeboxes installed, it was a large alehouse with speakers dotted around the walls, but there was also a speaker in the bottom of the freestanding jukebox unit. All was well Sunday to Thursday, but come Friday & Saturday evening the CDs started skipping.
An engineer was duly called, on multiple occasions, each time they were baffled, but convinced that it was just dirt on the discs. So each time they went through cleaning each individual disc (there was 100 of them), but the next Friday or Saturday evening the music was skipping Norman Collier style again. After a couple of weeks of this I suggested that the speaker in the bottom of the jukebox was causing the problem, as the volume was cranked up on a Friday and Saturday night, this was putting more and more vibration into the unit. The engineers dismissed my suggestion and continued trying to clean the discs, but still didn't cure the problem.
A couple of weeks later I turned up for work to find a shiny new speaker mounted on the wall above the jukebox, the one in the bottom of the unit having been disconnected and the wiring redirected. Lo and behold, no more skipping discs, so the lowly barman was right all along!!
In fairness anyone who doesn't listen to what the barperson or shop person (of the old, corner shop style - not your mega-hyper-super marts) is saying is at least one of three things:
1. Deaf
2. Some kind of Manglement
3. An idiot (regardless of pieces of paper held)
And someone in a bar / pub / establishment wot dun sells alcohol who triggers some of those rules tend to end up under the... loving... attentions of the Security staff. Kind, lovely people who have such wonderful senses of humour...
It's a bit like, many years ago, I called the RAC. The car kept misfiring. He did things with the distributor, but it didn't get better and he called for a tow truck. I pointed out that there was an electrical sound being picked up by the radio.He rather loftily told me it was nothing to do with the radio and refused to listen when I told him I didn't say it was the radio, but that it was the sort of sound you get when there's a spark and it was in time with the engine. He just repeated it was nothing to do with the radio....
It was a short
The garage found the problem almost instantly, after I'd told them about the noise on the radio As in the guy saying "Ah yes that'll be the (whatever it was*)". A two minute fix.
*I think it was a high power lead with carbon inside it or something. It was a long time ago.
Started working at a software company once. They had an issue where their servers seemed to be fine overnight but started failing in the daytime when people came into the office. Seemed worse in winter too.
Servers, well PCs, were all in a store room. As was a radiator. I noticed the thermostatic valve for the radiator was sitting on a shelf, and not attached to the radiator inlet. Room was unbearably hot too, because the radiator was scalding hot. I put valve back on radiator and closed off the valve, and server problems mysteriously disappeared as if by magic. I lasted about 6 weeks at that company.
I remember some hair pulling and swearing over the partition to the next desk.
When the customer typed a command in - it worked. If he ran it in a script/program - it didn't work. They both ran on our systems. It was the identical command so why didn't it work on the customer system.
Someone else wandered over and said "get them to edit the script/program and retype the command".
We could hear the eye rolling at the far end, but he did it as he was desperate . tap tap tap - " it works!"
The customer had cut and pasted from a manual into the file. Unfortunately somewhere in the process a quoted string became a string with back quote, and forward quote - which looked like a quote at each end (or may be a code page problem).
The nightmare of people using Word (or similar) as a text editor to create config scripts for a router, only to find it has automatically changed things to 'smart quotes', 'hyphens' and other weird $#!t like invisible formatting characters.
I recently had to try and explain to someone that they couldn't use '£' in a password because the router only understands 7-bit USASCII, which doesn't include '£'... and, no, they can't assume it will automatically be changed to '#' because you can't assume the server (which did accepted it) will do the same, and you can't easily check before installing the kit as the passwords get encrypted
(from memory USASCII is codepage 437 and UKASCII is cp 850, but all bets are off because the character was probably UTF-8)
The first Amazon Kindle I bought, had a speling corektor which also worked on the username and password boxes. It took me a while to figure out how to disable that, after which the thing was actually quite nice, but I have wondered what ordinary mortals thought of it and how many were returned in disgust.
Reminds me of something my father once did, even though it has nothing to do with IT.
He was a maintenance supervisor for a meat packing facility and that involved being responsible for the ammonia based cooling systems. One day there is much hemming and hawing about how to keep a specific room cool in the winter. My father points out that there's a door on the roof of that particular room, and live a climate which frequently sees sub-zero temperatures, so instead of actively cooling the area using ammonia, why not just open the door on the roof and avail themselves of the free cold air outside? This ridiculously obvious in hindsight idea ended up saving the company large amounts of money at all their facilities in colder winter climates and has become something of an inside joke within the family.
Eco friendly directive at a University datacentre during a hot summer.
Open vents in the roof to allow the hot air to escape.
Didn't realise that in many climates, prolonged hot periods are followed by thunderstorms.
AIrcon cost saved were possibly in the 100s. Replacement parts for damaged servers/switches in the thousands.
Sometimes we get bogged down by assumptions and preconceived ideas, while someone else who is not as intimately familiar with the system can come in with fresh eyes and analyze things from first principles to discover things that we overlooked because we immediately jumped to the conclusion that “it must be a problem with X”. And maybe 99% of the time it is a problem with X, so we don’t even think of checking anything else.
On more than one occasion I have spent all day working on some persistent, annoying problem only to go home to bed and wake up in the early hours of the morning with the answer having miraculously appeared in my head whilst asleep. I now keep a pen and pad in my bedside drawer to record these moments.
I think it's the fact that you have the more or less full picture of what you're working on in your head but if you're staring at a small amount of code on the screen you focus on that but it's not where the problem is. Once that block is removed a part of your brain is free to look at the whole picture. I've had a problem solved that way whilst just walking out of the door and across the car park but driving, and hence having something else to claim focus, was particularly effective.
On the rare occasions I've almost had to give up, I have phoned back to base to get help from the bench/workshop guys. Often, the answer arrives in my head during dialling, while the phone is ringing or sometimes as it's answered, at which I say "never mind, fixed it now". As you say, it's just getting away from the issue, away from the concentration on specific detail, letting your brain do it's thing and see the big picture.
My technique used to be to explain it to the "cardboard superman", "rubber duck", or whatever is the term in your area.
Now if all else fails I try to write everything in an email to my most knowledgeable colleague, thinking about how I would react to each part of the description and that usually helps me to find the issue.