My son's XBOX has gone on the fritz. We are getting error 14,16,21 all with different games. No mods at all that I am aware of. 6 months ago I sent it away to get the DVD drive replaced and all worked. Worked for about 5 months. It started doing the "require service screen" again so I sent it away again. They found no problems at all so they sent it back. Worked for 2 weeks and went to the "service required" screen with error 14, 16, and 21. Lights flash red!! I know how to take it apart. And I know how to insert games. I don't plan on soft modding or hard modding this uit. What can a father do to fix this XBOX?