I've messed up and used a generic LCD cleaning product on a glass iMac screen. According to the label it consists of distilled water and surfactants (or surface-active components, don't know how to translate it correctly). As a result there are smudges on the screen. Any way to remove them?
I have done this safely before with windex. Just spray a little on a microfiber or even a soft towel and wipe down the screen. As long as you do not drown it you will be fine.
I have taken the glass off the iMac before to work inside it and they do a good job sealing the insides from the out.
In general, when cleaning a computer, distilled water is fine as it is non-conductive.
Some Macs come with a microfiber cloth that works pretty well cleaning the screen. If yours didn't (or you lost it) you can pick one up at places like Amazon.com or Walmart.
The type of microfiber cloth that I'm referring to can be seen here at Amazon. A search returns lots of simulated terry-cloth microfiber towels (e.g.), which might work, but I recommend something like the first link.
You definitely want to be careful so as not to damage the anti-glare coating that Apple puts on your screen at the factory. Though this method does stray from the official cleaning instructions from Apple, I've had very good results using the following method to get a pristine, streak-free screen which honors the clarity of the Retina displays on my iMac 27" and MacBook Pro.
- Use either (a) warm water, or (b) a cleaning solution specifically made for Apple screens. (I found one called iKlear at Fry's here in San Diego, which is specifically made for displays on Apple products). Apply the solution (or water) to a clean microfiber cloth, then wipe the screen down with it. As others have mentioned, try to use the one that came with your iMac. Otherwise, just purchase a replacement (get one that is specifically made for cleaning computer displays).
- Get a nice shower squeegee. I always make sure to clean the squeegee blade off first. Use the squeegee to carefully pull the remaining cleaning solution to the edge of the screen (while the display is still wet). Catch the dripping solution with your microfiber cloth as you get close to the edge of the screen. Don't try to use a dirty or old squeegee. I'd recommend one like this.
Let me share with you how I came to this. My screen was heavily smudged. I tried water, dish water, glass cleaner, vinegar, and it only got worse. So I figured I did not have much to lose and I tried spray Lemon Pledge furniture polish. I sprayed it on, rubbed and cleaned with a soft cloth, then polished with a very clean cloth. My screen is now almost perfect 98 out of 100 + the surface is not as sticky as it used to be. It seems more finger print resistant and the dust blows right off.