Lcd dv3250 not working

the fact that you have on screen display tells me that you are on a blank digital channel, or input with no signal. check to see if this is so on all of your inputs DVD, VCR, Cable, Sat box... if there is no signal still, replace the scaler board.
here's the four basic components to a LCD tv.
1. panel. there is on board electronic inside not componet level repaired.
2. power supply. this feeds power to the unit 5V, 24V, and 15V. the 5V is the standby voltage while the 24V supply the inverters.
3. the inverters. this is a DC to DC inverer used to light the lamp. these and not component level repaired.
4. the scaler board. this is the board that runs the show. it sends the signal to the panel to paint the picture.also sends commands to the power supply to turn on the inverters. this board is definatly not component level repaired. most all of the boards can not be repaired at the component level, power supply may be the only one, but not all power supplies can be.
there is one other part to the set that does have failures and that is the cable connecting the panel to the scaler. this is the LVDS cable. sometimes just reseting the cable can solve many problems.
so based on this info your panel is working because you have onscreen display. your iverters are working because without the lamps you would not see the on screen. your power supply is working because you have inverters working. and the only thing left is the scaler this provides the on screen so we know that it is at least partly working.