Hello all,
I have an iMac G3 Indigo that appears to have some yellowing, either to the translucent casing or to the plastic that is underneath.
I am wondering, first of all, how difficult these are to take apart. I have seen some youtube videos of people taking them apart, but most of them do not involve removing these plastic case parts, or the ones that do seem to be doing it wrong and do a lot of damage to the case.
Second of all, if I can remove these plastic case parts, can this problem be solved using retrobrite? I have had success with it in the past when using it on beige plastics.
I really do not want to crack/break the case in any way. But the yellow-ness of the iMac is depressing. I remember what iMacs looked like back when they were new; their appearance was half of what attracted me to them.
Take apart is as follows … well some precautions and expectations: It is a bit difficult in that there are some plastic tabs that are likely to crack but won't be missed when put back together, unfortunately they get so brittle that cracking is inevitable. The outer shell is stubborn in some places to take apart. You may feel hesitant because of their stubbornness to come apart but be patient and use some good plastic spudgers.
I have taken apart a snow iMac so I can speak from experience. The plastic tabs that I am referring to, if broken will not affect anything, they broke on mine, they actually shatter to bits because of age and a poor choice of plastics on Apple's part (my opinion). The plastic that may break is not the original exterior plastic but is a plastic face that is housed over the front and top of the CRT and is a layer of plastic inside the main plastic.
The exterior plastic is tough, it appears at times as though it might crack while being taken apart but won't it's seriously strong but still be gentle and patient. I am sure it has a breaking point. Use plastic spudgers to ween the outer plastic loose.
The plastic tabs that may break are under the main plastic. I've marked them for you.
Yellowing.
This is likely due to some kind of dust.
Also, that inner plastic that I referred to can be better seen in the photos below. Here I marked on two areas that might crack but those are not it, from what I remember they are small parts of the same type of plastic that go on those holes. Also, this plastic might yellow, in fact I think it may very well yellow so try some of your 'retrobrite' material slightly diluted in strength, I recommend this as this plastic appears kind of brittle, at least the small parts that I have trouble finding an image of were and the plastic part you see below (over the face of the CRT) is of the same type as far as I can tell.
An iMac on its' side. Notice the the plastic, which goes over the CRT, appears whiter on the lower (on the right of this image) than the rest of the plastic, could be due to more exposure to sunlight.
Once you wash all the main plastics in clean water with a little detergent they will come back to life. It's a marvelous transition in fact as the plastics inside are absolutely covered in dust most of the time.
Recommendations
I would suggest you consider removing any scratches on the exterior of the plastic housing to really get a great result.
SAFETY
Please be careful with the CRT, it is fragile, don't handle it by the neck and please discharge the CRT. Don't let anyone tell you that this is not important. Have someone in the room when you discharge in case something happens but make sure that person is not near you. Remove all jewelry and don't wear clothes that are made of synthetics. Do not ground yourself. Keep one hand behind your back when discharging to avoid shocking your heart. Take these precautions when discharging the CRT. To be fair the iMacs and most CRTs have a bleeder resistor that discharges the CRT but if that resistor fails that screen is charged and can hold a charge for a very long time indeed. DO NOT TAKE RISKS.
What else? Hmm. Well, have plenty of space around you when taking apart and keep track of screws etc, this machine has a lot of parts in it so in summary;
1) Follow CRT Safety
2) Outer plastic can be challenging to remove and take apart but patience is a virtue.
If you have ANY other questions please let us know.
Kindest regards
—Alex Santos
