and I thought my PC was bad.
It's been over three years since El Reg readers rocked the IT world to the very foundations on which it rests with chilling photographic evidence of the horrors which lurk within PCs worldwide. Interior of smoker's G5 Cheese Grater after five years abuse, courtesy of John Boyarsky Twelve months later, and the shockers just …
I find that MOST cleaning jobs get by with the PC plugged in and earthed (avoids static discharges), and a DRY compressed air line, feeding one of the gun / probe type air blower things, with about 5 - 10 PSI or 30 - 60Kpa, outside or in a cross breeze....
LOW air pressure works quite well without spinning your fans up to 90,000,000 RPM - 2000V DC generators, with buckled bearings and burnt balls, and it shifts all of the crap out of and off everything quite well to boot.
Just saying - that because you can get 100 - 120 PSI / 7Bar / ~720 - 900Kpa out of a compressor, doesn't mean you should be force feeding it into your computer....
I use both a vacuum and an air compressor to get the shit out of dirt choked PC's. I turn the air pressure down to about 2 PSI, and stick the (plastic) vacuum nozzle over the dirt pile and give it a short blast of air. Why, simples, I don't want to breathe that shit.
The next task is to determine what O/S the machine runs. If it is not in compliance with WROK PALCE's Linux ONLY policy, it gets nuked from orbit.
As the maid says: "I don't do windows!!" ( http://www.rojisan.com/roj/humor/DontDoWindows.jpg )
Dairy farms are the worst as they have pc's running the parlour equipment and these are fly magnets. I wish I had taken a picture of the one which I had to replace a mobo, it wasn't just 'brown' in fly muck, but was thick in it. The guy thought I was bringing a new pc back as it was a cleaned beige box when I returned it.
We once had a laptop in with "liquid damage to the keyboard" and I rang the customer to ask what the liquid was, because after taking the keyboard off, it smelt of neither beer or coffee. He replied "well, not to put too fine a point on it, it's snot... I have pretty nuclear sneezes!". I washed my hands after that
I once took a synthesiser that belonged to my brother to be repaired. The bloke took the bottom panel off (this was a Roland SH-101 - simple to disassemble) and started picking at the flaky brown stuff stuck to the bottom of the keys. "What's this?" he asked. "Beer sick" I replied. He wasn't at all phased by my response, saying that it was at least better than the Yamaha DX-7 he'd recently fixed after the owners iguana had peed on it.
I found a dead mouse once. A mammal. Inside a PC. Poor little beastie had inserted its head between an Opteron's cooling fan and the heatsink. I really hope that this broke the beastie's neck, because otherwise its death was horrible in the extreme.
I then spent ages studying the case trying to convince myself that it had any hole that a mouse could squeeze through. I couldn't. But it must have managed it somehow.
Another time I took the side off a PC and bits of dust started hopping around ... the cat had had a flea problem.
If I get a PC dropped off that looks like a vision of hell inside, then when I take it back I know their house will be a hellhole.
Never fails. Yes people live in conditions that look like those photos.
Since I've been a roving IT tech I've been quite amazed at how many people live in total shitholes. These aren't 'poor' people, these are folks living in large barn conversions that must have cost £400k+. The new BMW 530i is outside but inside, your skin crawls.
Have some self-respect people!
Blow don't suck.
I used to be quite free with hoovers around the inside of PC cases, but I used the hoover on one and it killed the graphics card. Not sure why (static? hit it?, bad luck?) but since then I tend to have the hoover close by and encourage the dust/fluff (flust?) towards the nozzle.
I also recommend anything that lifts the PC off the ground/carpet and further up from the source of the dust.
I just need to go photograph the old desktop that father-in-law has installed in his workshop. He's a bit of a woodworker, so it could be educational.
quote: "I used to be quite free with hoovers around the inside of PC cases, but I used the hoover on one and it killed the graphics card. Not sure why (static? hit it?, bad luck?)"
The plastic bristles tend to get statically charged while in use; I'd recommend not using the brush attachment and just use the nozzle, which can also get statically charged while in use. I'd therefore also recommend making sure the equipment is off at the socket, but with the mains cable (and therefore the earth) still attached, and earth the nozzle on the case prior to actually poking about.
If you want to be really safe, then use (dried) compressed air to blow all the crap out and vacuum it up from there. I don't tend to bother though, I'd rather risk component damage than spray everything that's inside the case all over the room instead >.<
Most of the fluff and dust in a PC is doing no harm. The exception is the fluff that gets blown down between the heatsink fins, which makes it run hotter and ultimately throttles its performance.
It got blown in so you have to suck it out. Make sure that you immobilize the fan blade with a finger, otherwise the reverse airstream from the hoover may rev your heatsink fan to destruction.
The usual hoover crevice tool is too large. I use a length of PCV oval electrical duct pushed into the crevice tool, that's narrow enough to get down between the fan blades.
... inside was the standard anti-static warning on a Sun label. Underneath was a further label, in neat handwriting, attached, I presume, by a previous tech. It posed the following riddle.
Before, dear user, you hoover this horrible dusty mess, answer me this question:
What's the difference between a Vacuum Cleaner and a Van de Graaf generator?
Wether you suck or blow don't let the fan on the CPU or graphics card spin up in the airflow, the voltages produced can & often do fry some hardware. Personally I use a dust-buster and 1" soft paintbrush. Newbies of course go for the can of compressed air and bitterly regret launching the subsequent cloud of toxic cr#p.
Ah, the memories of going out to a 'remote site' housed in a construction office trailer to look at a dead system, popping the case cover open only to find the entire interior coated liberally in mouse droppings.
We did have one machine come in that was so absolutely coated in cigarette tar and smoke that the entire machine was a lost cause. The owner of it had a fit that the extended warranty company wouldn't cover it's repair/replacement either.
"They work as generators when set in rotation by airstream"
Nah, I don't believe this. Switched-reluctance fan motors do not make good generators. What's more, I've just tried it.
Equipment: Papst 12V ex-PC fan (tested and working), DMM, Industrial compressed airline
Method: Connect fan to DMM. Blast with compressed air at close range.
Result: Even when the fan made a noise like a dental drill, the meter showed no more than 0.3VDC.
Conclusion, Based on a sample of one unit, switched-reluctance fans do not make useful (or dangerous) generators. An AC induction motor may indeed high voltage when spun up, but I've never encountered one in a PC. YMMV.
Had a Kyocera tech "on site" once to do maintenance on a heavy duty laser printer. Pointed him towards the (grayisch) unit, got that answer. Well it WAS one of theirs (barely a year old). So he opened the unit and the next question was "what is that black dust in here?" One of the guys in the "office" dryly replied: "Coal dust. We dig that stuff out of the ground right there" pointing to the nearby mine shaft...
After cleaning the thing and replacing a small field-replaceable part the unit worked just fine again. Okay, it took some time and a quick swig of brandy to convince the tech that the office would not fall of the wall (where it was attached) when the mine hoist started working (it was in the building the office was attached to)
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