Some TV, depending on the model may not work, or not be fully functional if you use Universal remote.
If the TV has a blue screen it may be a source problem. Try connecting a DVD or a VCR, possibly through SCART cable that starts automatically
Also if the green light on TV is blinking and the TV has a blue screen, the TV may be in protect mode because of a fault.
Try unplugging the TV from main and plug it back, if that does not work, and changing connected source did not solve the problem, the TV may be faulty.
If you want to purchase and test an original remote, you can find one here:
Panasonic PVDF2703 Replacement Remote Control.The remote will come with a One Year Money Back Guarantee.
Regards.