My sony dru-840a

yes my sony burner du-840a will not burn mermorex 8x rw/tdk 4x rw sony 4x rw why not on the infor it read it will burn 8x but my

A bit more information would be helpful.

Has your Sony DU-840a burned any media? and if so, which media has it been able to burn successfully?

Also, which operating system are you using and which application are you using to burn your dvds?

yes it has burn verbatim 6x rw/sony dvd-rw/16xverbatim no ridata 8x rw/ memorexdvd-r yes

yes i am used dvd fab gold 5.060 i just try to burn i used verbatim dvd+rw it did not burn same thing and and my it read dirty disk also my tdk rw also my memorex dvd+rw same thing so i used my sony 830a same disk my tdk/verbatim both dvd+rw it went well but not my memorex 8x no so what next thank you for infor