white screen problem in w850

[rapidroll]

You have to full flash the phone means main+fs+customization but i think the best solution for you is SEUS,find in google and download,install it and select your phone,follow instructions.Seus will do all for you if the phone was never updated.

Edit:if after flashing problem persist then it is hardware problem and you'll have to take it to some repair shop.

UPDATE: SEUS now updates all db2020 phones to CID53 hence disabling SeTool 2 lite and XS++ support for your phone. not only that SEUS use the new software for the phone is downloded directly from the Internet and it does not have to be interrupted with anything.so if internet connection is very slow and consecutive. so do not update your phone with SEUS.