It's a first generation unit.

At times the playing of an original DVD will degenerate into a scrambled pattern where up to 1/3 of it has the video chopped into rectangles about this size (ignore the dots)

 ___
|......|
|......|
|___ |


that are in the wrong place in the picture (they seem to be part of the image, but incorrectly placed)

At the same time, it tends to freeze up, and the audio does too.
It doesn't help to try to skip to the next chapter, and fast forward, rewind, stop & play, nothing seems to get it out of this.  The media appears to be in good shape, no smears / scratches, etc.

But if you start all over and go to a different chapter right away, that one will often play OK.

Some discs play flawlessly.

The  manual isn't available.

Is there a way to correctly clean the optical lens or laser (whatever reads it) at home?    Not sure if I saw anything at the store for this.

yes you can get cd-dvd cleaners at disc jockey, target, walmart places like that

This is total heresay but i was told that playing DVDs in your XBox was bad for the unit.  A friend of my little brother's had parents who owned a Video/DVD/Gaming Rental store and they were adament that playing DVDs in the Xbox was a very bad thing (despite the fact that you can purchase the remote just for doing so).

Quoted: yes you can get cd-dvd cleaners at disc jockey, target, walmart places like that

To clean the unit, or the media???

Your DVD player is probably about to die.

You can swap it out for a new one pretty cheap.

Check out this site for all your X box needs.

www.xboxscene.com/

Nice forums here too.

Quoted: Quoted: yes you can get cd-dvd cleaners at disc jockey, target, walmart places like that To clean the unit, or the media???

now that u mention it both! it will clean the drive.  and they have some that can repair scratches cd's

Thanks, all.  Will get back on this thread after I check it out.

I used to fix xboxes and ps2's for a living.  All games for the xbox are dvd's.  You need to clean the laser lens.  To do this you need to remove the 6 screws on the underside of the unit.  They are located under the 4 rubber feet and under 2 of the stickers.  Once they are removed,  lift the cover of the unit off.  If the unit is facing you the dvd drive is on the left, the hard drive on the right.  Between the two drives is a screw (on the black plastic support trays).  Remove it and unplug the hard drive and lift it out of the unit.   The dvd drive is held in to the support tray by two clips towards the back of the unit.  Unplug it and remove from the unit.  Depending on the type of drive (thompson, samsung, etc) there should be 2-4 screws to remove the lid to the dvd drive.  Once they are removed, lift the cover off revealing the laser.  Take a Q-tip and some alcohol and clean the lens off.  Reassemble in reverse order.   MAKE SURE IT IS UNPLUGGED BEFORE DOING ANY REPAIRS.  Email/PM me if you have questions

Quoted: I used to fix xboxes and ps2's for a living.  All games for the xbox are dvd's.  You need to clean the laser lens.  To do this you need to remove the 6 screws on the underside of the unit.  They are located under the 4 rubber feet and under 2 of the stickers.  Once they are removed,  lift the cover of the unit off.  If the unit is facing you the dvd drive is on the left, the hard drive on the right.  Between the two drives is a screw (on the black plastic support trays).  Remove it and unplug the hard drive and lift it out of the unit.   The dvd drive is held in to the support tray by two clips towards the back of the unit.  Unplug it and remove from the unit.  Depending on the type of drive (thompson, samsung, etc) there should be 2-4 screws to remove the lid to the dvd drive.  Once they are removed, lift the cover off revealing the laser.  Take a Q-tip and some alcohol and clean the lens off.  Reassemble in reverse order.   MAKE SURE IT IS UNPLUGGED BEFORE DOING ANY REPAIRS.  Email/PM me if you have questions

Now THIS is the best info I've found on this site yet!