Thre seems to be no power getting to tv as the red on light does not come on

Some board further in the TV after the power supply has died. Take it to a repair shop.

Some board further in the TV than the power supply has died. Take it to a repair shop

You might need a new housing! Sometimes, the housing can be damaged with a new bulb and it can caused the TV to want to shut off.

3 times standby red light blinking shows that lamp cover has not been placed back properly after lamp replacement.
Make sure lamp cover, (the first thing that you removed to replace lamp in tv) is fixed securely then turn tv On.

Ur backlight video board is dead,must replaced.

One thing could be to check if your aerial is the correct one,(presuming you are in uk) for digital tv.
I have noticed that thre has been alot of questions regarding insignia tvs ,i suggest search this site.

I would initially suspect IC7001 and/or IC7002 on the D board. Those are your convergence output IC's. Those tend to fail after 5-10 years of typical use. Part# STK392-150 is available as a direct drop-in replacement part and repeat failures are almost unheard of. Also, check the low-ohm feedback resistors around these chips. R7011, 7012, 7013, 7014, 7015 and R7016 should all be 2.2 ohms @ 2 watts. If you have a shop do this, the typical price including travel and house call is $300-400. Parts alone are about $50, give or take.

1st check the fuses-----then the globes-----check all the fuses some have multiple tasks if you have a test light ,youcan test to see if thre is power on one or both sidesof the fuses with the lightswitch on.if thre is no power there the swich is the next place to checkfor power to those items not working. i cant remember if there is a relay on those ,but look for one

most of the time the led in front of the tv will blink red and that will tell the technician wich circuit to look in. if it does blink at all when it shuts down then the problem is more than likely in the power supply. the part number for that is 313819875691