360 does not read discs.
My 360 can't read disc, but I can access the dashboard without any problem.
I tried the following:
1. taking the 360 apart and cleaning the lens with rubbing alcohol and a Q-tip.
2. Using compressed air to clear any dust.
3. replacing the disk-drive itself, but still having it not read any discs.
On occasion, some disc will be be to play but eventually I'll get a disc-read error.
I think i can answer your question:
You mention you take the Xbox 360 apart to try and fix it - the actual problem is caused by overheating on the main sensors on the back of the drive and once they get too hot you have this problem.
The drive actually shuts down to prevent damage.
For more help with this problem you can view my profile.
First off, you need to make sure that the disc are not damaged or scratched up that you are putting in the system. If the games are newer and you know they work in other systems, then the drive still will need to repaired.
Dust is the drives enemy and can cause very many problems even getting dust under the laser lens and causing the laser to be replaced.
my xbox 360 would not read disk. if you check the laser eye it mite be all the way back. when it reads the disk it should start in and read out but when you cut it off it goes to the back position. and it mite get stuck in that back position. all i did was cut a small tip of an eraser of a pencil and glued it to the back where the laser eye hits. and it worked ever since