i need to replace matshita uj-840d in hp pavilion dv4000
And your question is ? BTW myself I wouldn't install another Matshita drive as these are known to be trouble
I have this one:http://www.myce.com/review/Hammer-Storage-MATSHITA-DVD-RAM-SW-9585-DVD-Burner-Review-103/ It has burned several DVDs with no problem. It is still in my older computer. The only reason I don't use it now is there isn't a firmware update that alows setting the booktype to DVD-ROM . The DVDs it has burned play fine on my settop.