>>>On-Call reckons he probably wouldn't mind an even stronger air compressor to get through some of the problems he faces now.<<<
Yes, yes indeed. We once had a problem, we implement SAP, we now dream of having that original problem back...
Welcome again to On-Call, El Reg's regular Friday feature in which readers share their recollections of being asked to fix follies. This week, meet “Bill”, who in the early 2000s did IT support for an engineering company. One fine day, Bill was assigned the task of sorting out a broken inkjet printer. “I visited the site and …
I did that once - put a sticker on label printers to tell users to put the rolls in the correct way so I wouldn't get calls stating "Printer not working".
The users then either -
a) Ignore the sticker.
b) Peel it off to see what's underneath, then scibbled in biro what I had put on the sticker then a)
... I had to caution people against using common or garden industrial compressed air for dusting out computers for several reasons. The primary was "lots must be better", and I'm here to tell you that an unregulated 90CFM @ 200PSI will not just rip DIPs out of their sockets and send key caps flying, but it will also lift traces off of PC boards ... And of course, even if they regulated it down to a more manageable volume/pressure, they still didn't use an inline dryer/oil separator, thus blasting delicate electronic components with rusty, greasy water. I can't tell you how many times I was brought in to clean up the mess from the mid '70s to the late 80's. Fun. Not.
Then there were the idiots who decided to put all matter of computer gear into ultrasonic cleaning tanks filled with one variety of "freon" or another, thus either completely dissolving or turning to goo the packaging of one or more components of the equipment.
Most freons in ultrasonic baths are pretty kind to most plastics.
What they are not kind to, however, is the gunk that should NOT be removed , like switch lubricants, and delicate labelling of panels ....
Which does tend to upset the shop floor when they discover the damage done to the next production run by the contaminated bath ...
Oh - and don't ultrasonically clean anything with a vacuum device in it - like nixie tubes.
Oh well - showing my age again.
I'm actually surprised more people don't get hurt by these. I've got a big commercial compressor in my workshop and it does a nice job of cleaning old computers. It's also nice for cleaning the workshop dust off my clothes when I've been in the shop. But whenever I do that I can't help thinking just how easy it would be to get too near my eyes, or even more scary, my ears. I could end up deaf in a fraction of a second if I didn't exercise care. Anyway, I highly recommend a real compressor for cleaning out dust bunnies in old desktops and for regular keyboard maintenance. One just needs to exercise a little care and pay attention to just how much stress one is putting on the item at hand.
"injecting air into the bloodstream." I have been wondering about that. Had to stay some time in a hopital and there was this plastic bag of something "healthy" connected to me with a thin plastic tube. Looking at that tube I asked the nice lady where all those bubbles of air moving into me, end up. She wasn't all that amused and after some hesitation - into your lungs. The next time she had the bubbles out, customer service. Anybody outside IT who actually knows more about that topic.
Also I have known a few guys here in Finland who worked for SAP and quite happy with their fate. And yes, I don't know their customers.
I have also known some Indian programmers with well working brains.
So now that I have become, mean as I am, the first ever commentard on ElReg with a kind word both for SAP and some Indian programmers feel free to give me an up or down.
Re. air in IV lines - it's a theoretical issue. Generally because the bag is higher than your body the air won't ever actually enter your bloodstream, the bubbles gradually work their way back up line. There is a concept of an "air embolus" which is where a significant amount of air (or other gas) is directly injected into a vein. If enough is put in in one go it can end up in the heart and cause the pump to fail, just like an airlock in any fluid pump - the ventricle will contract and compress the air rather than moving it forward. This does actually require quite a lot of air in one go. It's possible to do this over a period of time, but not a very long period as small bubbles will get absorbed.
Regarding a "hypospray" - it generally won't end up in the bloodstream, air or liquid pushed against the skin in force will likely just cause abrasions, i.e. separation of the top layers of skin as you see when someone has slid along the ground from a sports or road accident. The jet injectors that are available will push a medicine under the skin, not into the bloodstream - this works for some vaccinations but not for most medicines sadly. We have nothing like the Star Trek hypospray sadly.
-- medical doctor, former engineer who lurks on The Register....
I'd worry more about the compressor itself than the fact you might end up deaf by some freak accident (I've never heard of anyone instantly deafening themselves with a compressor?).
Most compressor accidents are either air needles caused when some idiots decide to try and inflate the apprentices overalls in a stupid joke and shove a nozzle up the apprentices overalls, which ends up occasionally with air being injected into the poor sods bloodstream and killing them.
The second major cause is the compressor letting go, there is a LOT of stored energy in that tank and its devistating when it pops due to rust or failure.
I have a 3 phase industrial compressor servicing my home shop, but I choose for it to live in its own brick small outbuilding. Then I don't have to listen to it droning on and if it blows up one day, I dont end up dead.
A hopefully apocryphal but common tale of airline injuries in workshops, involve a blast of air against the overalled backside of someone leaning over. This can cause seperation of the cheeks and air entering the colon, which can easily burst.
Industrial vacuum cleaners can be just as lethal, if someone was dumb enough to inspect a blocked intake too closely it could suck the air out of the chest collapsing the lungs.
I remeber when I was doing more arty things being warned about the pressure used for spraying from airbrushes (the fine pen sized ones not industrial), above a certain PSI it basically became a hypospray (jet injector for the pedants, and no I didnt know thats it's proper tem either), like in hospitals but with paint.
I agree, but as with all compressed air jobs, use with care.
A good mantra is "You know electricity can be dangerous, right? Compressed air more so."
I do use workshop air for cleaning appropriate electronic equipment, carefully.
I've always been cautious, especially with fans. Just what kind of an emf / spike can be generated by a fan being spun at a gazillion rpm? There's bound to be some residual magnetism in there somewhere, even for an induction motor. And, if there's no moisture in the air, What about static?
Anyway, I want the dust OUT not compressed into a corner somewhere.
"Industrial vacuum cleaners can be just as lethal, if someone was dumb enough to inspect a blocked intake too closely it could suck the air out of the chest collapsing the lungs."
To be fair, that's not the usual failure mode for human / vacuum cleaner interaction. At least, not for the male portion of humanity...
Just came back from a training weekend down south in Orange County (same airport as Harrison Ford "Schmucked up his aircraft landing") & tale of a high pressure steam leakage on a submarine was told to me by one of the attendees (quite a few ex-navy attendees actually).
When a pin prick leak occurs in a high pressure steam pipe, it's visible as a "cloud" in the general vicinity, when that's spotted all in the immediate area freeze & slowly look about for something within arms reach to use as a guide like a spanner or wrench as the North Americans have it, then move it in the general area of the cloud to find where it intersects with the leak, the results are pretty obvious once it does so.
A newbie submariner, forgot all his training on his trip out, spotted the leak & immediately went to point it out to his shipmates (he was also in an area of the boat he wasn't really supposed to be in) inadvertently using his arm as the detection device.
His forearm connected with the high pressure steam jet & a Anakin Skywalker type injury occurred, as the jet sliced through the flesh & bone severing without hope of re-attachment (Both sides of the wound cauterized instantly).
I had this very very old and very dusty PC from a rock grinding mill control system (yes, very fine rock powder everywhere) that needed to be cleaned. I had an oversized air compressor. I have TRIED to be kind, regulating air flow by gently pulling the air gun trigger, and it sort of worked. No components flying around. But I forgot to hold the cpu fan in place, so it went spinning at about 100.000 RPM, generated a lot of current (a motor is a generator, too) and totally fried something. The PC never booted again.
with a factory fixed airline. I did, admittedly, have some help from someone that knew how to use the line... which included the foresight to put an appropriate attachment on the line to ensure we didn't blow the components away.
It was an old, and very heavy IBM band printer choked with paper dust. Made out of battleship strength (and weight) steel with almost no small components paper side.
Another hazard of industrial airline air is that it can be delivered, rarefied I think the term was, with tiny amounts of lubricating oil which may or may not be good for your target, and is certainly not good for people!
Anyone old enough to remember the old Tektronix valved scopes?
the ones that ate half a kilowatt or more, and were much prized when the heating failed?
Wacking great fan at the back?
We used to blow them out with a 90 psi airline. Just do it outside in the car park and stand upwind of the dustcloud.
The closest I can get to that story is a printer that was blown up by a lightning strike.
* BANG *
Power goes out.
And through the wall, in the room next door I can hear some really odd clattering sounds.
I go to investigate and find parts from our office dot matrix printer scattered liberally around the room.
Its a good thing no-one was in the room at the time as some of the bits probably flew with some force.
Well, someone who was in DEC FS with me specialised on printers. Of course that makes sense when you're running multi page per second band and drum printers, but he was the only one willing and able to deal with the LCP01 inkjet. Which didn't yet have the throw-out-and-replace-with-new-printhead-with-cartridge way of 'cleaning', it had tubes and reservoirs and pumps and gubbins and doodads that invariably gummed up three days after your latest print. He was known as Johan Dammit because of his way of expressing his opinion of all things printer (and most other things electromechanical), but he was the guy who managed to *fix* your printer. Which, in the case of the LCP01 was no mean feat, and involved him ending up like a Jackson Pollock canvas.
well, 1984-ish.. in my metalwork class at school, they had a poster on the wall. It was pretty to-the-point.
TWO WAYS TO BLOW YOUR BRAINS OUT
A picture of a fired gun against a head, with brains ejecting out the other side
A picture of a compressor and its hose against a head, with brains ejecting out the other side
You could say the message worked, as I remember it clearly over 30 years later.
I did a similar thing to myself recently after making a trip to Colorado to get some of that industrial strength left-handed cigarette material. After consuming about a third of a not large one, I decided I needed to clean the evidence off the keyboard. In a dimly light closet there’s two similar cans, both with red straws sticking out of them…
I think my typing speed went up 20-25 wpm for the next few days.
"I remember seeing a melted HP LJ III in one of the offices..."
I presume it was still a fully working? I just retired one working LJ III. Over 25 years in a shitty metal works office - the print quality was fine, but it was just too slow to warm up and the 5(?) ppm just didn't cut it anymore.
..one engineer decided a Proliant 7000 was running hot because the PSU fans were clogged up and full of crap.
He decided to given them a clean with a can of compressed air.
Rule One. Disconnect power.
If rule one is not observed, result will be a loud bang and one very knackered, very expensive server.
Making them inhale the dead flesh of their colleagues.
In my home server room I (roughly once a year) shut everything down and, using a hand vacuum, clean out the servers in the acoustic case.
Not that much human dust, more cat fur, fine sawdust from the cat trays and, doubtless, dried cat-sick..
 Yes - I have a server room at home. Doesn't everyone? It has a stairgate across the door in winter (so it can warm the upstairs) and the door is shut in summer and the aircon gets switched on. Both irritate our senior female cat immensely as it deprives her access to a nice warm room
 The server room is next to our bedroom. Newer server makes a lot less noise but it's still noticable, even with the acoustic case.
 Having 6 cats, 5 of whom are rescues and 2 of them were really quite ill when they arrived and still are prone to vomit at the least excuse. After having a 24-port switch destroyed when a cat vomited over it, I decided to implemet access control.
 It still has two servers in the room. But the old Dell 2950 with the 8 15K RPM SAS drives is no longer switched on. Which makes thengs a lot more quiet. The new server has SSD storage..
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