Bootup Screen for Plusnet Mobile Network

[#1]

I moved from THREE network to Plusnet Mobile yesterday, and also ported my former phone number into the Plusnet Mobile network.  Hurrah !   All is working well and I had my old number ported within 36 hours.

What bugs me is my Samsung S8+ phone when it boots up. It shows a huge bright (near blinding at 7:00am) welcome screen announding "THREE NETWORK" for all to see I am a THREE network user. Bootup in a cinema and every one shouts at THREE.  But since this week I dumped THREE for PLUSNET.

How do I get PLUSNET to update that welcome screen (darker also), of instert my own bootup screen?

[#2]

The bootup screen is nothing to do with the SIM card.  You will have bought the phone from Three and they will have burnt their firmware onto the phone so that it supports their Wifi calling setup etc.  To get rid of the logo and Three customisation's you need to replace the firmware with the STOCK Samsung S8+ firmware.

Have a look at here https://www.sammobile.com/firmwares/galaxy-s8-plus/SM-G955F/ I would not attempt to flash your phone with new firmware unless you are absolutely sure you know what you are doing as there is a strong possibility that you will brick the device so that it never works again. 

[#3]

Very interesting article @flanzm

As I see it my S8 regularly flashed it self with an updated o/s, the most recent being an update from Nougat to Oreo.  This is all done without any input from me except to press the "Do I Now option". What I call a Push operation.

Correct: The phone was purchased from THREE and I later swopped the 3 network sim to an EE network sim provided by Plusnet. Can you tell me who is responsible for Push'ing future o/s updates to my device? Is it:-

a) Three?

b) Samsung or Sammobile?

c) Plusnet?

d) EE or BT?

I could not discover a STOCK firmware for S8+ on Sammoble.com. Is it therefore the case in the past either a) or b) above Push'ed the Sammobile referenced  G955FXXU4CRI5 / CRI1  (HSG) firmware to my device?   If this is the case, would not Plusnet or EE  send PDA and/or CSC firmware to my device from now on and so that my device becomes fully compatible with the network and corporate splash page?

[#4 · Accepted solution]

Your phone is running branded THREE firmware.  The phone periodically checks for new firmware updates and downloads them from THREE servers, so it is actually PULLING updated software.  Assuming that the firmware doesn't check the operator of the SIM card being used and also doesn't mind that you aren't a THREE customer anymore then I would expect it to continue receiving updates of the THREE firmware.

PlusNet do not supply phones, or have their own firmware so you will never get a PlusNet branded firmware complete with Logo.  If you think about it all PlusNet have done is supply you with a SIM card which you are using, as far as your phone is concerned it's still running THREE firmware and 'belongs' to THREE.  The SIM and firmware are two things which are completely separate and not connected at all.

If you want to get rid of the logo and THREE customisations then you need to install the United Kingdom (BTU) firmware.  Once installed updates will come directly from Samsung and not via any communications provider.  If you want to go down this route I would suggest posting on the Sammobile forum as someone there will have direct experience of trying to do what you want to do.

Out of interest - what functionality do you think you are missing ?  You are aware that PlusNet don't support Wifi calling ?  In which case I would imagine it only the logo which is annoying you ?

[#5]

Thanks very much indeed - this fixes my mind (problem) on actions to consider.

I am marking your last reply as "Fixed my Problem" also.

PS:

"Out of interest - what functionality do you think you are missing ?  You are aware that PlusNet don't support Wifi calling ?  In which case I would imagine it only the logo which is annoying you ?"

reply:-

My sole issue is was the THREE splash screen. Everything otherwise seems correct.  I thought it might be possible to write to only this file providing format and size was unchanged.