Can you confirm other items plugged into the power strip are working (power is getting to the power strip\extension)?
Ok, next thing to check is that you havent pulled the power cable out of the back of the TV, it may have come loose when you were reaching round to unplug the TV.
I dont think it is the power supply, not if you had disconnected the TV before you had electrical works done.
Most Panasonic power boards I have seen show a flashing light when you try and turn them on, when the unit is totally dead, its more often than not the extension lead, the fuse in the plug, or the fuse within the power board.
The only thing this model has is a power drain feature, where you can hold your finger on the power button while its unplugged for 60 seconds, then plug it back in, however I dont think this will help in your situation.
Do you have a spare TV power lead you can try?
Its ruling out the fuse has blown more than anything
Certainly I havent come across a unit which has become completely dead when powering it on at the wall (I have heard it happening, but wouldnt say its common).
With the Panasonics they are normally rather fault tolerant compared to Toshiba and other brands.
If you find a spare mains power lead, or swap the fuse int he plug and it still doesnt fix it, then the next step would be to get the machine into a service centre to be looked at, within a few minutes with a multi meter they can tell you if its the power board.