Default Display/GPU Help Needed

hi guys
i have a c6683 zu and have some annoying display problems
when i unlock the screen it gets vertical colored lines and then goes blank
i have to lock-unlock a few times to get to the homescreen
i've read that it's a sony software&hardaware issue
some broken update from them unlocked full frequency of the GPU and now it's messed up
is there a workaround?
i have the official .136 firmware
PLS HELP ME

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