I have a panasonic tv. Last night it made a popping sound (like when there is a black out) but when I tried to turn the tv back on the screen remained balck and it made a hissing sound. Has the tv completely broken or is there anything I can do?

Appears to be a power supply issue with everything being so dead.

time to take it in for a proper diasgnosis and then to decide if to fix or not

There could be a few things that would cause this. I would suspect that you have a problem with either the power supply board or the main board. Based on my experience, the main boards go before the power supplies. What is the model #

Unplug the TV. Replug in the TV. If it's still there, you probably have a bad panel. Try changing inputs. These panels are non-repairable.

Need model number and blink code at time of defect.

hey Al more than likelly it was the fuse that popped if you take the back panel off the fuse is next to the power cord and should take a 6.3 amp 125-250 volt fuse

It sounds lamp in tv got broken as you heard pop sound of it, replace lamp in tv to fix the issue.
Blinking light would be Lamp light at tv front that shows lamp is dead.
Lamp replacement procedure is easy and mentioned in tv user manual.
Thanks.

How many times this light flases in TV?

I think that the pop you heard was an electrolytic capacitor blowing its top on the picture frame board. If you are able to check this for yourself by looking on the board for the one/s with a bulging top or are a brownish/black colour like something has caught fire. And also in this situation smell can be of great help as it will smell burnt out but PLEASE before putting your nose or anything else in the tv take all necessary precautions against electric shock and discharge any electrolytic capacitors in the vicinity. If you are not able to do this yourself find a competant technician. Hope this helps.

I would suggest to read what other members have reported by clicking here.
Good Luck.