The tablet needs to be opened up to be diagnosed.
It could be any of 3 things:
a) LCD cable is loose
b) LCD itself is damaged
https://www.aliexpress.com/item/New-8-inch-LCD-DIsplay-Touch-Screen-Digitizer-Assembly-For-Asus-Zenpad-8-0-Z380-Z380KL/32808293829.html?spm=2114.01010208.3.1.tvs5ly&ws_ab_test=searchweb0_0,searchweb201602_3_10152_10065_10151_10130_10068_436_10136_10137_10157_10060_10138_10155_10062_10156_10154_10056_10055_10054_10059_10099_10103_10102_10096_10147_10052_10053_10107_10050_10142_10051_10084_10083_10080_10082_10081_10178_10110_10111_10112_10113_10114_10181_10183_10182_10185_10078_10079_10073_10070_10123-10102,searchweb201603_1,ppcSwitch_7&btsid=1a233326-0d49-4fce-8bd0-1e0bbd757b8d&algo_expid=67fd7a74-1467-46e9-a3cf-df3efd57b68f-3&algo_pvid=67fd7a74-1467-46e9-a3cf-df3efd57b68f
c) Logic Board is damaged
iFixit does have a disassembly guide.
[guide|53249]
The tablet needs to be opened up to be diagnosed.
It could be any of 3 things:
a) LCD cable is loose
b) LCD itself is damaged
https://www.aliexpress.com/item/New-8-inch-LCD-DIsplay-Touch-Screen-Digitizer-Assembly-For-Asus-Zenpad-8-0-Z380-Z380KL/32808293829.html?spm=2114.01010208.3.1.tvs5ly&ws_ab_test=searchweb0_0,searchweb201602_3_10152_10065_10151_10130_10068_436_10136_10137_10157_10060_10138_10155_10062_10156_10154_10056_10055_10054_10059_10099_10103_10102_10096_10147_10052_10053_10107_10050_10142_10051_10084_10083_10080_10082_10081_10178_10110_10111_10112_10113_10114_10181_10183_10182_10185_10078_10079_10073_10070_10123-10102,searchweb201603_1,ppcSwitch_7&btsid=1a233326-0d49-4fce-8bd0-1e0bbd757b8d&algo_expid=67fd7a74-1467-46e9-a3cf-df3efd57b68f-3&algo_pvid=67fd7a74-1467-46e9-a3cf-df3efd57b68f
c) Logic Board is damaged
iFixit does have a disassembly guide.
[guide|53249]
The tablet needs to be opened up to be diagnosed.
It could be any of 3 things:
a) LCD cable is loose
b) LCD itself is damaged
https://www.aliexpress.com/item/New-8-inch-LCD-DIsplay-Touch-Screen-Digitizer-Assembly-For-Asus-Zenpad-8-0-Z380-Z380KL/32808293829.html?spm=2114.01010208.3.1.tvs5ly&ws_ab_test=searchweb0_0,searchweb201602_3_10152_10065_10151_10130_10068_436_10136_10137_10157_10060_10138_10155_10062_10156_10154_10056_10055_10054_10059_10099_10103_10102_10096_10147_10052_10053_10107_10050_10142_10051_10084_10083_10080_10082_10081_10178_10110_10111_10112_10113_10114_10181_10183_10182_10185_10078_10079_10073_10070_10123-10102,searchweb201603_1,ppcSwitch_7&btsid=1a233326-0d49-4fce-8bd0-1e0bbd757b8d&algo_expid=67fd7a74-1467-46e9-a3cf-df3efd57b68f-3&algo_pvid=67fd7a74-1467-46e9-a3cf-df3efd57b68f
c) Logic Board is damaged
iFixit does have a disassembly guide.
[guide|53249]