i have a 1901fp monitor that when you turn it on flashes the picture for a second then goes black with the power button still green

i have attempted to use this monitor with both dvi and vga on at least 3 different computers

i am unable to find warrenty information due to the fact that i cant find a service tag on the monitor, and due to the fact that this company has over 50 dell computers and the monitors that come with a pc dont always get deployed with that same pc i am unable to determine with pc this monitor came with for its service tag

when i try to contact costomer support i have to have a service tag to beable to even email them or anything, even calling in you need it, i have found the model number and the 20 digit part number, but even with this information i cant even search for the warrenty or to see if i can fix or replace the monitor.

is there somewhere on the monitor that i can find the service tag or any way to just get technical supports email so i can contact them directly.

also i do not have a order number also due to the fact that we have a rather large number of dells and it would take a very long time to go through all our records to find one simple number that shouldnt be needed if we have the part number