Phone screen updates very slowly

[Rickmaersk]

Xperia XZ2

I'm on my second replacement screen (not sure if this is even relevant, this one is an aftermarket screen not a Sony OEM part, it worked ok for a month or two).

Phone was updated to android 10 with plenty of spare memory and no perfomance issues.
Recently I ran out of battery power and when I got it charged and restarted the screen was updating very slowly.
Eventually I tried a factory reset (Android8) and safe mode but it doesnt make any difference.

When it boots up it take about 30 seconds to draw an android logo that should take about 2 seconds. You can see each frame. I'm assuming it might be a display specific issue because if you actually had the patience you could get it to (for example) play music and it was smooth not glitchy.

I don't have another screen that I could test it with. Can anyone suggest a way of diagnosing if the screen itself is faulty of if it's another hardware issue.

 

[Rukbat]

Phone was updated to android 10 ... Recently I ran out of battery power

That's a good way to pay for a replacement battery. Recharge at 45%-50%. If it gets down to 40% and you can't charge it, turn the phone off!

Eventually I tried a factory reset (Android8)

No, a factory reset just deletes anything you've done (apps and data), it doesn't change the OS.

When it boots up it take about 30 seconds to draw an android logo that should take about 2 seconds. You can see each frame. I'm assuming it might be a display specific issue because if you actually had the patience you could get it to (for example) play music and it was smooth not glitchy.

It's most likely some app you have running at startup that's consuming almost all resources. Start in safe mode - if that fixes it, it's an app.

Can anyone suggest a way of diagnosing if the screen itself is faulty of if it's another hardware issue.

Not without replacing the screen or connecting the screen to a different phone.

 

[Rickmaersk]

Hi Rukbat
Thanks for your comments. I tried safe mode again but if hasn't made any difference so I'm assuming it's not an app.