right ..
i read alot on your forum about the problem with disc read error and close tray problem ...
i read sorting out the calibration of the pot and thought il try the rubber band tweek first ..
so i flashed a hitachi drive 046 rom version and it would not recognise any media discs at all besides genuine games and movies..
list of discs it wouldnt recognise as follows
these are all burnt on a pioneer 111d (version 1.29) also a nec optric using image burn v2.2
media used
verbatum (dye mkm 001) (printable face)
ridisc 2.4x (dye mag do4) (printable face)
ridisc 2.4x (dye mag do1) (printable face)
ridisc 8x (dye RICOHJPND01) (printable face)
at first it would not recognise any of the above untill i did the rubber band trick .But then it would recognise VERBATUMS MKM001
Ok now i thought i was getting somewhere so then i tried the ridiscs but it still gave me tray closed error or cannot read disc error...
Now i played around with the rubber band to no avail at all .. (couple of hours gone now ) still only able to get the verbatums to work .. now all the above discs are working on my other 360 with the same dvd drive ..
i thought has no one gone down the route of trying to clean the laser itself

so i grabed the misses nail polish remover and grabbed a cotton ear bud and cleaned the laser to the best i thought i could ...
NOW ...>>>
i have verbatims and the ridisc 2.4x working everytime ...
so i then took the drive apart again and cleaned the laser more with the nail polish remover ..
NOW..>>> i have all the discs above working fully ..
all the above working have the rubber band trick applied ..
i removed the rubber band and all the above still work ..
my conclusion is CLEAN YOUR LASER FIRST BEFORE YOU DO RUBBER BAND OR POT CALIBRATION ...
like to say thanks to the lads who have posted about rubber band trick and pot calibration the TUT have been a great help ..
please post if cleaning the laser head has worked for you also ....
rgds Jaime