A40 either turns off itself or gets stuck at the startup screen and won't start/close

[Muppet0781]

Recently have found my phone has started to turn itself off.  It's always pretty much charged quite full as I don't use loads of apps. I did read some problems are due to recently downloaded apps but I can't think of any I've installed recently, as I don't tend to use them much

It's also getting stuck at the startup /close down screen - I see all the Samsung logo but cannot get it to turn off despite pressing the button and holding for a considerable time.

When it eventually decided to turn on this morning, the battery was 80%.

device care 99/100 - clicked on optimising to get to 100 storage

29.4/64autodownload is set up

checked my software is up to date

back up data is on

about 18 months old.  Any advice greatly appreciated

[BandOfBrothers · Accepted solution]

Here are some generic troubleshooting tips @Muppet0781 

Put the phone in Safe Mode which disables your downloaded app's but let's your stock app's keep working. If the issues stop then this highlights a downloaded app as the possible issue. Come out of Safe Mode and start deleting your most recent downloaded app's one at a time until it stops. https://www.samsung.com/uk/support/mobile-devices/how-to-start-my-galaxy-device-in-safe-mode/ 

Then try

Clear your phone's System Cache Files by turning your phone Off and then from a set series of button presses go into the phone's System Files and clear the cache. No information is lost this way. You may need to insert your headphones or hook upto a computer with your data cable to get to this menu on the phone. 

If all else fails then back up and then remove any relevant sd card and factory reset.

I wish you all the best with this. 

[DAVESHADY]

I had the same problem. tried factory reset but it still failed sent it back to Samsung and i got upgraded to Samsung galaxy A41 it's a common fault with the a40 the screen freezers and it shows Samsung logo for between 5 and 15 minutes then turns it self off then restarts it's self..ring the place you bought the phone from and you should get new phone

[Muppet0781]

many thanks, i'm attempting this now

[Muppet0781]

it's probably too old for a replacement, so I'll try the other tip I was given and if that fails, a new phone it is! 

At least I'm not alone lol.  Thanks for sharing