Schnider Electric Proface PS 5000 HMI is not starting

Dear Friends
i will glad to learn from your expirence regarding the issue which i am facing after power distrubance proface hmi start switching from white screen to black screen which i assume it's IPC could not start , checked HDD, RAM and Lithium Battery and found only 2.7 V on battery which i replaced with new now 3.1 V on battery , please can any one guide me regarding the solution or wayout from this trouble

thanks & regards
Ashique Ali WhatsApp Image 2022-03-06 at 11.01.08 AM.jpeg