I got my Xbox 360 250gb 3 years ago. I haven't touched it for almost a year, until recently when I got GTA V for Xbox 360. I realized the graphics seems very grainy and straight lines would appear to shimmer (especially for objects in the background). At first I thought it was a problem with my HDMI cable, but even when I used another one, or tried other games, the problem persists. Even the dashboard is affected. Since my console is obviously no longer covered by the warranty, is there any DIY fixes available?