Viper53 on a FreshAir II board does not start

[ignislion]

Good time of day!

Currently I'm trying to recover the main board from the air purifier. The Viper53 power controller burned out with part of its binding. I found on the Internet a part of a very similar circuit and other people with the same board and was able to restore burnt part. However, the controller still does not start.
The rectified voltage reaches the controller.
COMP = 0.8
TOVL~0
VDD~10

To start, the controller must charge the VDD capacitor to 11.5, but this does not happen and I still cannot understand why. And maybe I'm digging in the wrong direction at all. I would appreciate any comments, thanks!

There is a lot of garbage in the photo, sorry, the board has been on the shelf for 2 weeks.

https://oshwlab.com/wbnerd/fresh-air-ii-power-bd
https://static.chipdip.ru/lib/004/DOC001004759.pdf

[Andy Watson]

Is D10 short-circuit?

[ignislion]

Diod was replaced it works fine

[Andy Watson]

Oops! I had missed the VDD=10 and read it as VDD= 0.
Does VDD remain stable or does it pulse regularly? If it pulses, it suggests that the Viper53 is trying to start-up, but is being held-back by something.

The PCB around the Viper53 appears to have suffered some significant heat! I suspect that chip's demise was probably a symptom; not a cause. Could be just a trick of the light, however, there is a PCB track that  starts under R44 and travels north-east towards the low voltage test-points - looks like it has been over-heating. If this is so, that current must have originated in the transformer - i.e. it is highly likely that that is fried too - probably taking the Viper53 with it.

[ignislion]

Sorry! I may need to attach an image of how the board looked at start. The components were literraly roasted and blowed. So i replaced everything in regulator and loopback parts.

[ignislion]

IC8 - optocoupler was dead so i replaced it and anything near as well.