If you need to fix a chip, gouge or nick in an LCD display, you can do it with a dab of petroleum jelly and the edge of a credit card.
I bought a 20-inch LCD monitor off Craigslist for $25. The seller didn’t mention until we met–in a parking lot where I couldn’t test it, of course–that there was a small chip in the display, but he assured me it wasn’t noticeable. I bought it reluctantly. It wasn’t noticeable in his picture, but when I got it home, I could see it.
You won’t be able to fix it completely, but you can make problems like this a lot less noticeable with a dab of common household petroleum jelly. The reason a gouge is visible is because it refracts light differently from the rest of the surface, so if you can fill it in with something that refracts light more like the rest of the surface, you can make the gouge or nick a lot less noticeable.
Dab a small amount of petroleum jelly into the chip using a toothpick, repeating if you didn’t fill the chip completely the first time. Then smooth it flush with the edge of a credit card, using a vertical motion top to bottom followed by a horizontal motion.
The result isn’t perfect. I couldn’t get the defect to show up in a picture after I fixed it, which is good, but basically, when displaying light colors it looks like there’s a bit of a smudge on the screen. When displaying darker colors, it looks like one or two pixels are stuck white. Either case looks better than the chip.
If you have a damaged monitor, this fix should be enough to at least make it good enough to be a secondary display. Of course if you’re buying a secondhand monitor, the better answer is to ask up front in your initial query if the screen has any chips or scratches in it. Then, if the answer is affirmative, pay $10 more for an undamaged monitor or wait until next week.