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Abused, But Working Hardware Stories?
RPI Geek writes "Everyone's heard the stories about people who, knowingly or unknowingly, abuse their computers. Personally, I've had a faulty power supply literally burn a hole through the motherboard, with the only ill effects being a dead PCI slot and USB ports. I'm curious as to what kind of abuse fellow /.ers have done or seen done to electronics while the hardware still worked afterwards. Soldered a broken keyboard PCB back together so that it worked fine? Taken sticks of RAM out of a running computer to see when it would notice? Overclocked a 386... to 386MHz? I'm interested in hearing any stories about abused-but-working hardware."
I had an hp-48g in 8th grade. I used to play basketball before school with the 48 in my pocket (without the soft-cover, no less) and it would usually fall out of my pocket during play (onto hard asphault) about twice a week. In addition, I once dropped it into a puddle about 6 inches deep when I was getting out of the car (again, without the soft cover).Yet, the calculator still works perfectly, even if it has a few nicks (no majorly visible dents or anything though).
I guess this is a true testament to the quality of pre-Carly HP hardware.
Most likely what you heard was an electrolytic capacitor. They are used as filter capacitors for your power supply. Without them you may here some humming, but the amplifier will work fine.
Speakers rated 6V will most likely have 10V capacitors, which will explode in the way you describe when applying 18V AC.
To Terminate, or not to Terminate, that's the question - SCSIROB
I kept my Airport Base Station beneath a planter in my living room. One day I watered the plant and dripped some water on the base station. Fried immediately, the lovely smell of magic blue smoke - or so I thought.
I opened it and noticed the two main capacitors had bulging tops. Turns out the original Airport Base Station had poorly rated capacitors, and they were prone to dying. The bulging top is a clear sign of failure. A website explained which capacitors make appropriate replacements. For the 5 dollars it would cost I figured it was worth a try.
Turned out it was a good gamble. After soldering in the new capacitors the bloody thing worked again.
There are probably a few busted Airport Base Stations floating around out there - and well worth recovering. The older graphite model is the one with the poorly rated capacitors. Even if the base station itself can't be fixed it contains a Lucent wireless PCMCIA card which may be perfectly usable.
-- thinkyhead software and media
That guy is/was an idiot, and you're too if you think ESD is a myth. ESD can cause anything from no effect through intermittent problems to complete failure, depending on your luck mostly. Obviously older hardware with comparably huge transistors stand less of a chance to die from ESD, but even those are not immune. Don't even think about trying something similar with current hardware.
My point-n-shoot camera's viewfinder got dirty. I opened it to clean it out, and touched the capacitor for the flash light (12v). It knocked me unconcious and burned my hand.
Yeah, 12v can bite.
The flash capacitor is about 4kV, not 12V. The whining noise after you fire it is the inverter pumping the cap back up for the next shot. It's also not current-limited, delivering all power it can to the flashtube in a few milliseconds. The TV EHT supply you mention later *is* current limited hence it gives less of a perceived shock even though the voltage is much higher.
I've taken belts from a camera's flash cap before now; they made my arm muscles spasm and throw the camera across the room.
Unfotunately, you assume one very wrong thing...
Your skin has a "break down voltage", much like a diode has. Past a certain voltage, your skin no longer provides much resistance (I don't have the exact values) and so as voltage increases, your "hand to ground" resistance decreases. This causes the current to increase exponentially, not linearly.
So you are absolutely not safe in touching 240V.
Girmann
Nietzsche is dead. --God
NO. Sorry to shout, but I had to play safety-nazi on this one having seen the aftermath. It's actually easier to do yourself serious damage with DC than AC, and HV DC is very scary indeed. First off, as noted above there's a point around 600V where, despite the skin's apparently high resistance, it gives in like a diode breakdown and the current punches through the hard, horny outer dermis that is so resistive. Inside you are a nice squishy bag of saline solution, with very little resistance... Think about the old demo of cooking wieners with two nails and wall current.
Second major issue is that DC causes sustained muscle contraction so you grip involuntarily. AC changes direction, causing muscle contractions in sympathy with line frequency which gives you some chance of letting go/pushing clear. DC gives you no such option, and the effect is noticeable at quite low currents. Very, very dangerous.
Google for more info, but DC is not remotely 'safe'. If you must play with HV DC - anything over 50v basically, let alone valve (tube) amps - treat it like it will bite. Keep one hand behind your back, let someone watch within reach of the breaker, and use current limiting whenever possible.
It's your opinion that you use a better keyboard.
I've got a Microsoft Internet Keyboard that's served me well for about 4 years, even when clogged to the gills with cat hair. I've got the extra buttons mapped to stuff I need, and the Windows key is actually fairly useful, despite all the naysaying:
Win+L: Lock Station
Win+M: Minimise All Windows (Win+Shift+M to undo)
Win+D: Hide All Windows (Win+D again to undo)
Win+E: Open Explorer
Win+F: Open "Find File" Dialog
Win+R: Open "Run" Dialog
Does it make you happy you're so strange?