Why is plastic turning black?

[barb213ks]

:confused: Noticed the plastic on my monitor was turning black & used a cloth dampened with water to wipe it down yesterday & today is blacker than it was yesterday.....does anyone know what causes that to happen?

[Narue]

It's all of that radiation. You'd better invest in a Geiger counter.

[barb213ks]

Very Funny! Sounds strange but it has me concerned that something might be smoking & it's not me!

[HawkeVIPER]

Is it warm anywhere? Where exactly on the monitor is the 'blackness'?

[Narue]

>Very Funny!
I'm serious. Radiation and heat will discolor plastic over time. Check for hotspots on the case, odd happenings on the screen around the edges, and make sure that everything is kosher with the power coming in (not too much). If you see anything out of the ordinary besides discoloration, pretty much all you can do is replace the hardware. If you don't see anything else, I wouldn't worry about it.

[HawkeVIPER]

>Very Funny! I'm serious. Radiation and heat will discolor plastic over time. Check for hotspots on the case, odd happenings on the screen around the edges, and make sure that everything is kosher with the power coming in (not too much). If you see anything out of the ordinary besides discoloration, pretty much all you can do is replace the hardware. If you don't see anything else, I wouldn't worry about it.

Indeed. This sounds more heat related than rad related tho - plus, if it was leaking rads, he'd feel the effects from it pretty quickly... remember the days of un-sheilded monitors and headaches after an hour? =P

[barb213ks]

The only warm spots I feel is the cable modem sitting next to the monitor & the side next to the monitor is black also but think it's always been warm as I have it on all day. The monitor is less than a year old. How would I know if I got too much power coming in? We had a power outage for 4 days last week. Could a power surge when the electricity came back on cause it maybe?

[barb213ks]

The blackness is all over the monitor but mostly the front. I have had some headaches recently which is unusual for me but figured from staring at the screen too long.

[HawkeVIPER]

<1 year old means get it the hell back to whence it came and get a new one... that is a hairline in the shielding. I'd also stop using the monitor asap.

[pcpalct]

I agree with all of the above.

It is a health hazard and the monitors use should be immediately discontinued and a new one purchased (or as someone stated, under warranty monitors should be replaced for new ones...).

Be careful in the transport of the monitor to the box and make sure it doesn't crash around a lot. I know this sounds stupid, but taking some extra care around CRT never hurt anyone.

Good luck
:cool:

[Real-tiner]

It happened to me, and it was just the paint coming off (from friction where cables abraded). The plastic underneath is black on my monitor.

[HawkeVIPER]

With it causing her headaches, telling her that it's probably just some worn paint is probably a bad idea. Rads ARE dangers.

[Real-tiner]

You're kidding!

- First of all, nothing a monitor puts out could activate a Geiger Counter. They respond to only alpha, beta, and gamma rays. You need a NUCLEAR powered source to produce these. No electronics in a monitor can do that. A smoke alarm has nuclear materials, but not a computer monitor.

- Second, the only possible ionizing radiation that could come from a monitor is x-radiation. Any monitor made after 1980 has such a low powered supply that X radiation is highly unlikely - especially if the monitor continues to function.

- UV radiation is more likely to discolor plastic than x-radiation. But there is nothing in a monitor which can produce UV radiation. The sun and certain fluorescent lamps are sources of UV radiation. (One source is the after-hours sterilizing lamps used at doctors offices and veterinary clinics.)

- Is the sun shining on it?

- Infrared radiation could harm the plastic, but will not harm either humans or the plastic except in doses high enough to be felt as being hot.

- It is likely that the cause of the black on the monitor and the headaches are not related.

- Is the black stuff dirt? I have to constantly remove dirt attracted by the static electricity on the monitor tube face. And if kids have access, it probably IS grimy hand dirt.

- One remote possibility is a leaky microwave oven nearby.

- Another possibility is some solvent (even nail polish remover) being used in the area. Note that nail polish remover DOES cause headaches.

- Some cleaning solutions may discolor the plastic.

- If a winding is vibrating in the flyback transformer, it can produce a very high audio-frequency sound. This can cause headaches, but can't change the color of plastic.

- One time I found an office monitor coated with hair spray. The secretary who used it touched up her hair just before she left (using the shut-off monitor face as a mirror), and some residue from the spray collected on the monitor over time.

- I get headaches if I have to be in light produced by GE Octron fluorescent tubes. The are not continuous spectrum, but radiate at only 8 discrete line wavelengths. The company bought them because of their efficiency. Changing to Sylvania Cool White tubes fixed this.

[jwenting]

1) monitors give off X-rays. These can be detected by a Geiger counter if it's sensitive enough.
You apparently don't know much about EM radiation or you'd know this.

2) monitors are now shielded which reduces the emissions greatly. If that shielding is not working properly radiation can still get out.

3) either can do it easily. Both UV and X-radiation are EM and will affect plastics. Just because you are more familiar with UV radiation doing it doesn't mean it's the only cause.

--

5) UV can harm people as well and not just if it feels warm

6) it's possible though. What is more likely is the same defect to the hardware having 2 different effects, one of which shows up as the user getting headaches and the screen being discoloured.

[Real-tiner]

I used to work in X-ray crystallography, so I know about X-rays.

It is quite unlikely that it is X-radiation with today's designs. The high voltages are quite a bit lower than they were in the X-ray scare of the 1970s.

Higher X-ray frequencies ("hard" X-rays) are detectable on a geiger counter. But the x-rays from a TV are lower in frequency ("soft" X-rays). An X-ray phosphor and a scintillator tube are needed to detect these. The frequency varies directly with the applied voltage, which we did to change the diffraction patterns for analysis.

UV can harm people, but there is no mechanism for producing it in a monitor.

IR cannot do any damage other than heating something. It is not a penetrating radiation as far as the human body is concerned (neither is UV).

It is much more likely that the headaches and the blackening of the plastic are unrelated coincidences, because one cause needing the properties of both is much less likely than two independent causes.

Often headaches on the job are caused by non-physical causes, including the type of mental work, the difficulty of that work, or office politics. There were people in the 1990s who tried to ascribe those troubles to XLF (extremely low frequency) radiation. But their claims were all disproved.

I have now traced the removal of paint on my monitor to the cleaner the custodial staff uses. It seems to be a solvent for that particular paint. Come to think of it, that solvent could cause headaches too.

[jwenting]

if the screen is producing X-rays or whatever in large enough quantities to damage the molecular structure of the plastic casing (which is what the discolouration is) it's likely to be severely malfunctioning.
This can well have an effect in for example the refresh rate (which at incorrect settings can cause headaches) or the sharpness of the image (again, can cause headaches).

If you've traced it to the cleaners, then all's fine ;)
We've had to introduce a policy telling the cleaners to keep their dirty hands off of our computers and screens because they kept damaging them.
They had a habit of using copious amounts of water to clean everything, causing monitors and computers to short out.