Toshiba SD-M1802 reading problems

Hi, i have a toshiba sd m-1802, i flashed it’s firmware but still doesn’t read dvds, do you thing that i should clean the lens first?

Oh, i forgot to tell you that reads cd’s perfectly!!!

Flashing a firmware can never ever resolve hardware problems!

I thought at starters that the really problem were the less famous discs but, i guess that the real problem is of hardware nature. Do you have any ideas how can i repair it? I tried cleaning the lens but that did not help.