Question [Q] Chinese phablet bricked?

hi everybody,
just bought one of these cheap chinese phablets, 7 inch, dual sim.
type is:
Bassoon is also written on the back
cpu 6515a, gpu sgx531
android 4.1
worked quite nice but stuffed with chinese crap (samsung app-app in chinese, a strange nand error in wifi and some more).
Preinstalled and undeletable.
I succeeded to root (vroot) and installed supersu and rootappdelete.
Beeing uncareful in deleting the crap I destroyed or deleted obviously a system app which is responsible for the sreensaver..;-((((
Start, android screen, homescreen ....everything fine
swiping to unlock the screen works but leads to a flickering (frequ about 3 Hz) screen ...and nothing more.

A simple questions to the Xperts.....what to do now best?

Thanks in advance
Ps: Donīt have the stock rom nor a suitable custom rom