Tv does not turn on after a power outage. stand by power light blinks seven times

Please un-plug the cable between the main board & the power supply, apply the AC power to it, if the back lights come on & still on, replace the main board; if the back lights did not come on, mostly the problem is defective back light LED strips.

Have you when set turns off and standby or power light flash to count here the blinks if in a sequence like seven blinks, pause etc? This se should have the error buffer.

Seven blinks - High voltage shutdown. The high voltage has exceeded 33k and the unit goes immediately into safety shutdown. Check power supply regulation and horizontal circuits.
As you can see here, seven blinks of standby light is due to some over voltate at the final anode of the picture tube. This is a protection process that going on insde the tV circuits, to prevent more damage to other comnponents on board. The most common cause for this is with the main power regulator out voltage itself. If any way, it ahs exceeded 135VDC, this kind of fault will occur. Check the main power regulator section circuit for any damaged component/s. Replace all the small electrolytic capacitors there. Visit the site named 'Electro-help' for more details. Check this LINK and select the site named above. View it in 'Flip card' option, which can be selected from the drop down box menu at the left top corner or the display window. It will make search easy. Some times, the ads attached with each posts might help you to find the availability of spare parts. There are more than 550 posts to different brand TVs. Blinking codes and details are there.

Seven blinks - High voltage shutdown. The high voltage has exceeded 33k and the unit goes immediately into safety shutdown. Check power supply regulation and horizontal circuits.

• Seven blinks - High voltage shutdown. The high voltage has exceeded 33k and the unit goes immediately into safety shutdown. Check power supply regulation and horizontal circuits.
  

There is a High Voltage fault or power supply fault.
Hope that helps.

Can you unplug the TV for about 15 seconds, and then plug back in and watch the stand-by light. Tell me how many time the stand-by light blinks in regular intervals. If it doesn't blink at all, you need to change a fuse on the g-board. Once this is done run back through the stand-by blink light process, and more troubleshooting can be done if problem isn't already solved. If the stand-by light just keeps blinking with a count over ten just tell me, and I'll look for other possibilities.

if you have the circuit diagram of your tv,check the horizontal polarisation IC closer to the line transformer and replace it.If it doesn't work,send the question again.

Here you find sony blinking codes

SIX Blinks---No Horizontal (H STOP), no raster, goes to the blinking selfdiagnosis
function immediately. Check C515 & 516 and the jungle IC, IC206.

SEVEN Blinks---High voltage shutdown. The high voltage has exceeded 33k
and the unit goes immediately into safety shutdown. Check power supply
regulation and horizontal circuits.

First, the blinking light is a code, how many blinks? Second, regulators are not resettable. Don

try to re solder the power suply