How many flashes of the MPUs LED when you boot?
Lack of HV will not stop the game from booting only you will not have displays.
Did you repin the connectors to the rectifier board?
What about the test points on the SD/PS board?
Are all the boards original? If original boards make sure you reflow all the connector pin headers. Pay close attention to the solder connections to the flipper relay and neighboring connector header.