After receiving my G4 last week and digging into it, I found that LG is once again dual-sourcing (JDI and in-house LGD) panels for the G4, and that all most verifiable touchscreen issues I have recorded have been on JDI panel equipped devices (EDIT: Though the vast majority were JDI, there was at least one LGD with the same issue). The problem itself is EMI/noise related and is remedied by a solid path to ground (plugging it in, good contact with your hand, etc).
I have verified this with a few dozen phones so far, but more data would be helpful. If you're going to, however, please don't post if you just feel that your touchscreen isn't as responsive as you'd like (missed taps, etc). There's too much room for error there. To verify that your device has the issue, it is best to count the number of discreet touch events it can register both while unplugged and plugged-in/grounded. If your device has the issue, you will only get 5-6 before failure while unplugged and 10 while plugged-in. You can use the free app Display Tester from the play store to check.
As for determining which panel you have, the easiest way is to check your kernel message buffer immediately after boot using dmesg. If you're rooted you can do this on the device, if you aren't rooted you can use adb.
The oem will be in your kernel command line, panel name, etc.
NOTE: Though it appears that there is a hardware element to this issue, I do think it's possible that LG could fix it in the touch driver with a software update. I personally haven't updated to the firmware that was reported to fix this on my variant (vs98612a) as it was pulled, so I can't say firsthand.
I have verified this with a few dozen phones so far, but more data would be helpful. If you're going to, however, please don't post if you just feel that your touchscreen isn't as responsive as you'd like (missed taps, etc). There's too much room for error there. To verify that your device has the issue, it is best to count the number of discreet touch events it can register both while unplugged and plugged-in/grounded. If your device has the issue, you will only get 5-6 before failure while unplugged and 10 while plugged-in. You can use the free app Display Tester from the play store to check.
As for determining which panel you have, the easiest way is to check your kernel message buffer immediately after boot using dmesg. If you're rooted you can do this on the device, if you aren't rooted you can use adb.
Code:
dmesg | grep -i panel
NOTE: Though it appears that there is a hardware element to this issue, I do think it's possible that LG could fix it in the touch driver with a software update. I personally haven't updated to the firmware that was reported to fix this on my variant (vs98612a) as it was pulled, so I can't say firsthand.
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