Atomic I/O letters column #156Originally published 2014, in PC & Tech Authority
(in which Atomic magazine is now a section)
Reprinted here December 20, 2014 Last modified 18-Jan-2015.
Worse: Orange juice, nitric acid, molten iron
How bad is tea for electronics?
I'm not asking for myself, you understand. But if, hypothetically, someone had spilled a half-cup of tea (white, no sugar) into their laptop (ThinkPad X200) and then frantically pulled the battery and shook as much liquid out of the thing as they could, what are the odds the laptop will survive?
There are three basic ways in which spilled liquids kill computers.
The first way is by physically interfering with moving parts. While there is liquid in a hard drive, that drive will not be happy. When the liquid dries up, whatever solids it leaves behind can also interfere by filling the fantastically tiny gap between a hard-drive's heads and its platters, which is conceivably somewhat fixable by washing with distilled water and then powering the drive back up only long enough to recover data from it, but I wouldn't make any bets. Dried-up liquids can also cloud the lens in an optical drive, but that's pretty easy to clean; you can do it with a long cotton swab without even opening the drive up, if you're careful.
Fortunately, hard drives are pretty close to completely sealed. They have a little breather hole with a fibre filter over it to allow the air pressure inside the drive to equalise with the outside pressure (hard drives work in micro- or zero-gravity, but not in vacuum), but that vent is so tiny that it usually keeps even catastrophic spills from getting into the drive. If a drive isn't actually immersed in liquid, it'll probably stay dry inside.
(If your computer has an SSD instead of a moving-parts hard drive, of course, then even immersion probably won't kill the drive. I presume your little ThinkPad X200 also has no optical drive, so you don't have to worry about that either.)
The second way liquids kill computers is by corrosion. If a liquid is acidic and left on electronics for a while, it can damage circuit-board traces and some other components. Even clean water can cause corrosion if you leave it sitting there. (Or if you pump it through components made of different metals, as many car-owners and computer-water-coolers have discovered.)
The third way is by conductivity. Many beverages are electrically conductive enough to completely screw up the functionality of any circuits they're sitting on. The goo left by an evaporated beverage may also be conductive enough to be a problem.
The worst liquid that commonly gets spilled on computers is non-diet cola. Cola is quite acidic (a pH of two-point-something), it's highly conductive, it foams into every tiny cranny, and it contains huge amounts of sugar - Coca-Cola is about ten per cent sugar (or fructose...) by weight. So it leaves plenty of horrible goo when the water evaporates.
The best liquid that commonly gets spilled on computers is plain tap water. Water is not acidic, it's only very slightly conductive, and it leaves no evaporation residue worth worrying about on anything short of a hard-drive platter. If you dry a water-splashed computer out smartly so corrosion can't get going, it'll probably be fine.
Tea with no milk or sugar in it is chemically pretty close to water. If that's what you... hypothetically... spilled, then your computer would have an excellent prognosis, provided you can get it apart and dry it out.
Tea with milk and sugar would be significantly worse (Earl Grey might be acidic enough to do some damage!), but still not nearly as awful as cola.
With milk and no sugar? I reckon you'll be OK, provided you can take the laptop apart, clean it carefully (rinse with deionised water if you want to be fancy), dry it out, and reassemble. Even if you've never done this before, taking a modern laptop apart (and then having it work when you put it back together...) is usually quite easy. Most manufacturers have downloadable service manuals - a PDF service manual for the X200 and X200s is here - and all you need besides that are the right screwdrivers, plus maybe some random orangewood sticks or tongue depressors or guitar picks to use as spudgers.
(The only even slightly exotic screwdrivers you might need are actual Torx drivers, rather than the set of hex bits for an interchangeable-quarter-inch-tip screwdriver that I usually recommend. Torx and other hex-headed screws are pretty common in laptops, and may be down at the bottom of a little well that's too narrow for a standard hex bit.)
If I were you, I would definitely opt for doing this myself if I didn't have a computer-repair person who could look at it right now. Leaving the wet laptop on the shelf for a day while someone gets around to fixing it is not a good idea.
(Oh, and on the plus side, a wet computer is probably significantly more difficult to damage further if you take inadequate electrostatic discharge precautions while working on it!)
The part of a laptop that retains spilled liquid best is the keyboard, but cleaning that is pretty easy. Just detach the keyboard module, run plenty of water over and through it, and leave it to dry out in the sun for quite a lot longer than you'd think it'd need. This is to make sure there's no water lurking in the little rubber domes or between the layers of the key-matrix sandwich.
(Famously, you can clean a PC keyboard by putting it in the top rack of a dishwasher, and it'll probably work afterwards. I don't recommend you try this with an expensive keyboard, though, and laptop keyboard modules are often pretty pricey. Cleaning only the non-electronic parts in a dishwasher is much less risky, but also not greatly more convenient than just scrubbing those parts with soap and water.)
in days of yore I once discovered an Amiga 3000 (I told you it was days of yore) that'd been sitting under a roof leak and had dirty water literally sloshing around inside the case.
I poured the water out, gave everything a wipe, pointed a halogen floodlight at it for a few hours, and it was fine again. Even though the protective stickers had floated off a couple of UV-erasable EPROMs and I'd just subjected them to a few hours of moderate UV light.
Thinking very hard about nothing
You recently had a letter from someone who wanted a way to tell what Chrome tab was using tons of CPU time, and you told them to press shift-Escape to get the Chrome Task Manager. I've got the same problem and can use the same technique to spot the pages that do it. Usually it's an eBay page.
My question is, what is it about eBay, and rarely some other random site, that does this? Few to no other people seem to have this problem. I want to fix it, not just have a fast way to tell exactly where it is and have to close a tab to make it go away. So what's the next step?
When a popular site does something weird in a popular Web browser for not-very-many people, if the culprit isn't malware of some sort, it's likely to be a browser extension (or "add-on").
Finding a badly-behaved extension is pretty easy. Just disable all extensions (in Chrome, you do this via Settings -> Extensions), and see if the problem persists. If it doesn't, re-enable your extensions one at a time and see which one brings the problem back. It'll almost always be one extension, not some confusing combination.
This technique identified Pat's problem quickly enough: It was the relatively unpopular "FVD Downloader", for downloading streaming video files. I don't know why FVD particularly freaks out on eBay pages, but switching from FVD to the more popular "Video Downloader Professional" cured it.
Every time I press shift or alt or control there's a beep, and that key - they're called "modifier" keys, right? - is stuck on for the next letter. Like, if I want to write Dave I can press in sequence shift-d-a-v-e. I'm running Windows 7.
What the heck is going on?
You have "Sticky Keys" turned on.
In various recent Windows versions, a box to turn on Sticky Keys pops up if you press either Shift key five times. Five Shifts plus an Enter will thus turn it on, and this can happen by accident if a kid, cat or person in an altered mental state gets at your keyboard. Sticky Keys is really useful for people who for whatever reason cannot easily press two keys at once; for everybody else, it's a nuisance.
Sticky Keys and several of its relatives can be found in the keyboard section of the Control Panel "Ease of Access Center", which sounds like a government office where you can get on a three-year waiting list for a wheelchair. There is, for instance, "Mouse Keys", for controlling the pointer with the keyboard, and "Toggle Keys" (which you can activate by holding Num Lock down for a while) to beep when you press Caps-, Num- or Scroll-Lock. "Filter Keys" blocks accidental brief or repeated keystrokes; you can turn it on by holding down right-Shift. That's good for people with tremors, or trying to type while riding a horse.
(The Ease of Access Center contains numerous other disability-support sorts of features, best among which for practical-joke purposes is the screen-reading "Narrator".)