Touchscreen Problems after Lollipop Update

[Feomatar04]

Hello everyone,

I remember that within the past year, there were maybe 5 occasions in which my Xperia Z touchscreen wouldn't react. After turning the screen off and on again, it would be fine again.

Since the Lollipop update, this issue occurs 90% of the time. When I turn the screen on, the touch input doesn't work at all. Sometimes, it will start working after I turn the screen off and on several times. Somtimes a full restart of the phone does the trick. However, once the touch input is working, it works perfectly as long as the screen stays on.

Is this behaviour typical for a hardware defect and the occurrence after the update is just coincidence? (which, for me, would be somewhat hard to believe...)

Or is there anything on the software side that I should do/try?

Many thanks and best regards,

Philipp

[Uliwooly]

@Feomatar04

Reinstall Lollipop with PCC and report back

PC Companion (PCC)

Bridge (for Mac)

Alternatives on How to backup Xperias

http://talk.sonymobile.com/thread/36355

[Feomatar04]

Hello uliwooly,

thank you for your reply. I reinstalled Lollipop with PCC.

The problem is still occurring, but less often than before. Now the touchscreen seems to be disfunct about 25% of the time. This is all pretty subjective, so I cannot say for sure whether or not the reinstallation really changed anything, but it definitly feels that way.

Do you think I should try going back to 4.4.4? Is it worth a try? Or do you think it actually is a hardware defect?

All the best,

Feomatar

[Uliwooly · Accepted solution]

@Feomatar04

the only way to find out if it's a hardware issue will be to downgrade and test the screen.

[Feomatar04]

I downgraded the Phone to 4.4.4, but the touchscreen is still broken...

So it wasn't Lollipop.

Now I just have to figure out if it's worthwhile to repair it myself (~ 100 USD) or if I'll buy some other phone.

[Uliwooly]

@Feomatar04

replacing the Xperia Z's screen it's quite simple as long as you have the correct tools, if you don't have a heat gun, use a hair dryer, and take your time. 

[nfsfabio]

Hello Feomatar04... How are You? Let me say you... This case also happened with me... I have a Xperia Z and it was
Working properly before lollipop updating.. After updating, it happens the same thing your device... Im engineer... I belive That it was a software problem That damaged the touch screen...Im not sure but..i belive that you or me replace the touchscreen and keep the lollipop it can to damage the touch again.... The right procedure would be first of all to downgrade to kit kat 4.4.4 and after it replace touchscreen... What do you think?