Samsung galaxy a40

[Mar5311]

In the past week my Samsung a40 phone doesn't charge when switched on. I have tried a new charger and charging cable. If I power the phone off it will start to charge, if I charge it when off to 80% or there abouts I can then continue charging while the phone is switched on. Does anyone have any idea why this is happening. 

[BandOfBrothers]

First please look in the charging port with a 🔦 to see if there's any build up of lint. 

May I ask are you using an official Samsung Charger Plug and cable ?

There is a diagnostic tool found in your Samsung Members App. 

Also try >

• Clear Cache Files from the phone's System Partition Section  > https://www.samsung.com/uk/support/mobile-devices/how-do-i-clear-the-cache-on-my-device/ You may need to insert your earphones or hook upto a powered On Laptop or use a Tv's USB Port to access the Clear Partition Section. This may help with lag or stutters as this clears the phone of old/unused or broken cache files.There is also a Repair Apps option in the Menu System too. 

And a Samsung Service Centre can assess your phone. 

If I can be of any further help then please don't hesitate to ask.  😎 

[Mar5311]

Thank you both for giving me advice. The phone was charging this morning but not on fast charge. I did the diagnostic test and the only problem was the USB connection, at that time the phone was charging. The cable charging was OK. When doing the test for USB device I used the wall socket and then the USB port on my computer and got same result both times. Checked the charging port all okay. I'm using official Samsung charging plug, not sure about any of the 3 cables. It's strange I had yo power phone off yesterday to get it to charge and once it was powered back on again it started charging. This is the 2nd time this has happened.