[Android Q&A, Help & Troubleshooting] Feemy:
I have been using the Samsung galaxy note 4 for the best part of 10 months with no major issues, except the phone getting hot, most noticeably after the Lollipop update in April. From Wed 29th*July my phone has been freezing, and then immediately rebooting with no rhyme or reason; whether I’m on an important business phone call, checking business e-mails, using a messenger app, browsing the internet, or even if the phone is just sitting there untouched. On several occasions it will just appear to shut off or get stuck on the Samsung logo screen and the only way to rectify this is to pull the battery out. What’s worse is, the phone gets really hot during these reboots, and upon restart, the battery drains by 5-10%. In fact, the phone can get so hot that it is actually uncomfortable to place it in my pocket. And that’s just because of the reboots, and not general usage. Simply put, the phone is no longer fit for purpose.

The fault first appeared on 29th*July 2015. The phone just randomly restarted whilst I was using a messaging app. Then, during one of the several random reboots that occurred hereafter until Tuesday 4th August (the day I went to get my phone repaired), I got the message, “Downloading. Do not turn off target!!!”

The phone was stuck on this screen for 5 minutes, so I had to take the battery out to get it working again.

On another occasion I got a more sinister message, “Kernel panic upload mode” which really concerned me so I rang the nearest authorised Samsung repair centre – Fleet Mobile in New Eltham. However, after having a word with them, they said they don’t fix the Samsung Galaxy Note 4.

So my next port of call was the CRC Samsung Repair Centre in Surrey Quays. I spoke to them on the phone on Friday 31st*July, and explained my problem of constant rebooting and the inexplicable messages in as explained above, so they suggested I pay them a visit.

On Tues 4th*Aug 2015, I visited the CRC Samsung repair centre, and I told the assistant about the issue and the messages I received as per above. The assistant said he had never come across such a message before, so he went to ask the technician. He came back and said the technician too had never come across this message on an Android device, and that it was “only specific to iOS products”. So I asked if I could speak to the technician myself and tell him that I had seen this message on rebooting, but I was told by the assistant that the technician was too busy to have a word with me. He also said that the technician had been dealing in Android software for many years and had never seen this message appear. I wanted to tell the technician that this was not just specific to Apple products because I had witnessed it with my very own eyes.

So the assistant flashed the phone at the store and told me that it was taking a long time to boot. I was told they would have to keep it for 2 days. I asked what likely work would be carried out and his answer was, “that is something the technician would have to decide.”**So I asked him what his thoughts were, and he said it’s more than likely that it’s a hardware issue and that the motherboard (PBA) would be replaced free of charge.

Whilst at the repair centre on the day of collection (6th*Aug), I noticed that my Android version was 4.4.4, but my phone had 5.0.1 installed when I gave it in. At this point, the warranty was still intact. I gave the phone back to the assistant to update my phone to 5.0.1, and questioned him as to why this had happened. His reply was that even though the IMEI number of the phone had been transferred to the new motherboard, they forgot to update the software. I was obviously very suspect at this moment, because it showed poor workmanship and neglect.

On returning home that evening, the same reboot procedure happened again a couple of times, and my heart just sank because I truly thought that my phone would be fixed. During one of the reboots, I got the message, “"Kernel is not seandroid enforcing. Set warranty bit: kernel". I was hugely alarmed by this message and rang the service centre on Friday 7thAug, informing them of this. They suggested I bring the phone back in for repair.

The phone continued to get hot, freeze and continuously reboot multiple times last night. I ordered another battery from Amazon (total cost, £12.00) to see if it would help the situation. The following morning the phone was off even though it still had 50% battery the last night. I tried turning it on but it just wouldn’t switch on. I plugged the charger in and still it wouldn’t switch on. The new battery arrived today so I inserted that. To my amazement, the phone did not start up. I am now left with a completely unusable phone.*

Now Samsung are saying that due to these error messages, the Knox warranty has been tripped, so the warranty is void. They're suggesting that the phone has been rooted by myself by installing some unauthorised software. I've argued with them saying i have never even thought of rooting my phone because i wouldn't want to void the remaining 14 months warranty that is left on the phone. They have said i may have unintentionally installed some app that has caused the phone to be rooted. I only download apps from the Google play store. I even rang Google I up amd they verified that i had not installed any illegitimate apps.

My question is, can an app root a phone?? If so, how?

Does anyone know what caused the random reboots and the error messages described above. To me it sounds like a fatal hardware issue but Samsung are pretty sure it's software related. The problem i face now is that Samsung refuse to fix the phone for free because the warranty has been void, which i don't buy.

I'm wondering if they installed an old motherboard which may have been rooted, but they are adamant that they only replace with new motherboards.

Someone please help me out here. I am not willing to pay a single penny to get it fixed because I strongly stand by the fact that I have not rooted the phone and hence voided the warranty. Samsung Knox is a flawed security software.