16 June 2008, 20:07 | #1 |
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Partial yellowing?
My A1200 has never been exposed to sunlight, and only one day had a severe exposure to nicotine.\
Could this be the reason why some of the keys in the keyboard are ywllowing, and others are not? It's very annoying. I got a mint machine and now some keys are yellowy ;( But it was just one day! (though, in a club, first and last time I used my 1200 for VJing :P) |
16 June 2008, 21:19 | #2 |
Ya' like it Retr0?
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@Akira
the Yellowing as you know is the oxidization of the flame retardant chemicals added to the ABS plastic. Some internal light source like florescent light will actually act as a catalysis for the this oxidization. as much of not more so than regular sunlight. |
16 June 2008, 22:14 | #3 |
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So, why some rows are more yellow than the others?
The whole keyboard should be affected the same way (and i dont remember using it under any sort of fluorescent light, i hate those!) |
16 June 2008, 22:17 | #4 |
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On one of my A1200s, the '9' and '3' keys on the numerical keypad have yellowed quite badly, all other keys are as-new white. It must just be random.
Steve. |
16 June 2008, 22:18 | #5 |
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I've heard that a lot - that it's smoke and fluorescent light that causes it - but from my experience it's not that simple.
I had my A500 set up in a very smoky room beside a wood fireplace for 5 years and I've had it under fluorescent lights for at least 10 years - and it's still not yellowed at all. A Colour Computer 3 that I had carefully wrapped in a box in a closet for 15 years has ugly yellow patches and randomly yellow keys. An A4000 I just picked up (which was from a non-smoking bowling alley) has a perfectly white keyboard case, but half of the keys and spacebar are bright yellow. If the keys were exposed to the same conditions, why wouldn't they all be yellow and why not the case? I picked up a couple free A500s recently and they're unbelievably yellow. They're as yellow as a banana - maybe even more yellow. Imagine a banana that was dipped in industrial yellow paint then thrown into a sewer and you've got the idea. |
16 June 2008, 22:28 | #6 |
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So there's a mistery to solve here.
I want it solved with chemical formulaes and all ;D It never happend to me for any other computer, that some keys would yellow while others don't. So I am puzzled by my 1200 |
16 June 2008, 22:29 | #7 |
1 Potato to Spam´em all!
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Hummm, interesting, my A1200 is 16 years old, its case is still white as snow and in its keyboard only the space bar is really yellow, and in the numpad lightly yellowed keys are number 9 and 3 too.So i guess its not random.
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16 June 2008, 22:36 | #8 |
Thalion Webshrine
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I heard it depends on which fingers you use for typing which you also use to scratch your arse.
If it's the index finger on your right hand then YUHNJK yellow first where if it is the index finger on your left hand then RTFGCV yellow first and if you use both hands or a different finger it varies... |
16 June 2008, 22:40 | #9 | |
1 Potato to Spam´em all!
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To: alexh
Quote:
Last edited by Yoto; 16 June 2008 at 22:53. |
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16 June 2008, 23:11 | #10 |
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loffle!
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17 June 2008, 01:37 | #11 |
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Well that explains why my A500 keyboard hasn't yellowed - I don't scratch my arse. However, my boxed CoCo 3 that went yellow must have been wrapped in the plastic wrap that I wiped my arse with. (...and the very yellowed A500 must have been entirely up someone's arse...)
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17 June 2008, 02:58 | #12 |
I hate potatos and shirts
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@Alexh:
ROTFLOLASTC! Serious now: those random yellowing caps is a normal thing, I'm afraid. Think with me: those keyboard are made from a batch, right? Do you people know how plastic injection is made? Let me tell you. You have the injector with the caps matrix, plus a funnel in the injector where the plastic (in pellet form), colour masterbatch (white, in Amiga case), fire retardant (also in pellet form), plus some "charge" (usually, plastic scraps). Those components are hand-mixed and tossed at the injector's funnel. Some of those pellets are heavier than others (specially white masterbatches). With the machine vibration, the heavier pellets go to the bottom of the funnel, leaving lighter ones on top. As every injector operator knows, you need to add more auxiliars (add-ons) to the plastic formula to insure the final product have the minimal characteristics expected. So, in face of those behaviours, they put some "surplus" of fire retardant in the mix, who (since it is lighter than other pellets) stays on top of the funnel more than in the bottom. This results in some final pieces have more fire retardant than others, and even some without the product at all! |
17 June 2008, 09:48 | #13 |
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We need to track down the injector operator that worked on the spacebar and the 3 & 9 numerical pad keys, and lynch him!
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17 June 2008, 15:11 | #14 |
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I want the head of the one who worked in my row of yellowed keys.
OFF WITH THEIR HEADS! |
18 June 2008, 03:05 | #15 | |
I hate potatos and shirts
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Quote:
Today we have more accurate processes (on-line mixers and dosers, etc) and raw materials. But this is today! Last edited by rkauer; 02 July 2008 at 17:56. |
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18 June 2008, 03:33 | #16 | |
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Quote:
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02 July 2008, 08:29 | #17 |
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Just a thought that occurred to me last night... If our beloved machines (15+ years old) haven't started yellowing yet, can we assume that they won't ever yellow? Surely they'd have started by now? Are we lucky enough to have randomly got an Amiga without (or very little) fire retardant?
Steve. |
02 July 2008, 18:04 | #18 | |
I hate potatos and shirts
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Quote:
But don't count with "my Amiga still mint, it won't become yellow never". The more fire retardant, more of it will migrate to the surface. Even slight quantity of it will come to surface. It's a question of time. If your Amiga don't start yellowing in say 30 years, than you can say it won't become yellow... |
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02 July 2008, 18:53 | #19 |
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There is nothing we can do to avoid amiga cases from getting yellow, the truth is that the polymers that yellow the most probably had their stabilizing agents wrongly mixed.
The main yellowing agents are Ozone, UV radiation (either by direct sunlight or some lamps), humidity exposure, heat sources like gas or halogen heaters can sometimes act like a catalyst as well as some organic acids.Bad mixed polymers with stabilizing compounds will yellow earlyer than others, this is why some Cases and keyboards keys will turn yellow faster than others. We have to assume that Commodore had several plastic factories making cases and keys and some may had bad plastic mixtures, thus we dont know the proficency from most plastics used by Commodore, some may have been too many times recycled. |
03 July 2008, 10:22 | #20 |
2 heads are more than 1
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OK so, how do they burn?
The white ones burn better than yellow right? Anyone want to do a "scientific" experiment? |
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