When switching panasonic tv on it goes into standby

Please read the guide, right now only 5v standby power supply is working, it goes into standby because it sensing short circuits such as the backlight inverter board or failed DC filter caps in the power supply section.
If you are going to DIY and have proper tools, electronics knowledge, and know safety precaution then please read on:

Please see my basic troubleshooting guide here:
http://www.fixya.com/support/r5093881-lcd_flat_panel_tv_troubleshooting_guide

http://s807.photobucket.com/home/budm/allalbums

http://en.wikipedia.org/wiki/Capacitor_plague

Parts: www.shopjimmy.com
Capacitors kit: http://lcdalternatives.auctivacommerce.com/Default.aspx

Please post back what you find.

You must check your main board television, check the Horizontal output block , check Transistor horizontal output, test it with multi tester , check whether the transistor device is burned or not. and don't forget check output voltage ( B+) 115 Volt, it should exist. If exist and transistor is normal, you can check to electroli capacitor 110uf/160 Volt, wheather is good or not.

It is for sure that your set has encountered a fault in the power section in the main board. There could be either a failure or a break in the circuit. So first of all open and check the main power board for any signs of dry soldering joints. Use a good soldering iron and a good light to probe. Solder all possible areas specially ones closer to the power resistors and drives. next check the +B voltage, trace it or disconnect from the ddrive to confirm the failure. You must use a good multimeter to check from the power section which is working and is cutting off due to a failed feedback. If not familiar do not attempt but take help. I hope you can decide and try. Good day