2407WFP new or refurbished ?

What I must obtain from seller to have warranty working for me and what to check warranty...

Correct me if Im wrong, but I think I saw that in the firmware menu there is a value showing how much hours the monitor has worked?

I have no firmware. Where I can download this ?

Look at this on how to access the service menu. DO NOT TOUCH ANYTHING INSIDE, just take a look: http://www.dellcommunity.com/supportforums/board/message?board.id=dim_monitor&message.id=70187

It is possible by someone who sell that he will cheat hours of usage? It is possible to get working contrast because I have not this option in menu brightness !!!

As far as I know, it is not possible to alter the usage time (well, short of finding the where the flash memory is, deciphering it and altering the values and checksums, but that's not gonna happen). For the contrast, you can't touch it while working with DVI cable, try plugging DSUB if you are eager to see contrast. Ask dell why is that, sure there is some reason.

All you have to do is select "Reset timer" to clear the counter.

Eh, then it is a bad decision such an option is left there. No way to check it then ;(