Why won't my Xbox 360 read discs?

If the console will not read a disc, there is either a problem with the disc itself, or the laser in the Xbox that reads the discs. Fixing a problem with a disc can simply be a case of carefully wiping it down with a clean soft cloth, but a misaligned or damaged laser in the console itself is a more serious problem that may require repairs from a professional.

1. Locating the source of the problem
Finding out whether the problem lies with the disc itself, or the components in the console, is the first step to finding a solution. Trying a variety of game discs and DVDs in the console is the easiest way to do this, because if no discs work at all, the fault is likely to be with the laser itself.
2. Fixing the laser
If the problem is with the laser, then a common problem is dirt on the laser lens. There are a number of lens cleaner discs available that can clear away dust and dirt buildup, and often this will return the laser to normal working order. Be aware however, that tampering with the laser directly may cause a misalignment, which is a much more serious problem to fix.