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In lugnet.org.ca.rtltoronto, Chris Magno writes:
> that it looks like an ink stain underneath the glass. The good news is
> that it just happens to be in a place that there is nothing on the
> screen. The brick works JUST fine.
THe geekiness knowledge of dave comes thru...
the Liquid Crystal Display (LCD) of any unit that uses one (calculator, rcx,
watch, etc...) has two wafers of glass sandwiching the 'liquid crystal'.
when an electrical current travels thru the liquid crystal, the crystals all
line up in the same direction. with a polarizer filter (a little piece of
plastic on the front of the glass)
What happens when the glass breaks the liquid crystal leaks out. since the
plastic polarizer doesn't break, the crystals all hang out b/w the glass and
the plastic and since the plastic is a polarizer and the crystals are the
other part of the polarizer, it appears black, just as if an electrical
current is running thru it.
hardware wise, the electronic device still functions, and will function for
all eternity, as if nothings wrong. how would it know that the glass is
broken? the issue is that the liquid crystal is leaking out and will,
eventually, spread to cover the entire display, especially if you touch the
screen or jar the mechanism around (and it's an rcx, of course it's going to
be jarred around)
there's an old physics term for that but i can't remember it. it's like
having two panes of glass, one on top of another, and dipping one end in a
bin of water. the water eventually makes it's way up b/w the panes of
glass, until the entire area b/w the glass has water in it.
or for you chemistry geeks, remember when you used to prepare slides and
have the little piece of plastic on top of the glass slide. put a dab of
water on a corner of the plasic and it 'jumps' underneath the plastic and
distributes across the entire piece.
/end geekiness
dave
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Message has 2 Replies:
 | | Re: bad RCX
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| Dave: WOW. I new exactly what the "Ink spot" was but I never knew it was a spreadable thing. Based on your message I am going to return it. :( I was all prepared to make it my "special" brick but if what you say is true: "....is leaking out and (...) (24 years ago, 17-Mar-01, to lugnet.org.ca.rtltoronto)
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Message is in Reply To:
| | bad RCX
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| Ok, A moral question for the group. I just received (yet) another RCX brick. I ordered it At specturm, they ship mail or UPS, stuff arrives about 2 days later, and they are Canadian, and bill in Canadian dollars, and they sell to the public. Anyway, (...) (24 years ago, 16-Mar-01, to lugnet.org.ca.rtltoronto)
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