flashing 紅燈 is the preliminary diagnose (ie. just help you to 估到顯示壞乜版). It may not be the exact root cause of fatal failure.
If BGA component is involved, you may not be able to do DIY repair. Buy a new board is the only solution.
If 顯示壞 Power Supply 版, you may be OK to repair the board at minimal cost; and no need to buy a new board.
Good luck ~~