The HTC Thunderbolt 4G can now be updated with the Sense 3.5 Eternity custom ROM firmware, a tool which has just been released. Therefore, in today’s tutorial you will be able to learn how to apply this OS update in the easiest way possible. Also, you can discover the features and capabilities added by the same software into your phone internal system along with the so called “negative aspects”. The process is not hard to complete, but in order to do it as it should I recommend you to follow the steps from this how to guide.

You must learn how to install the Sense 3.5 Eternity custom ROM firmware on your HTC Thunderbolt 4G if you want to improve the appearance, power up the performances or gain more access over its Android based operating system. You will be able to customize and optimize the system, the phone being your new playground. Also, the features added are numerous and I know you will find them appealing. But we will discuss about this a little bit later.

Now, the release of the present update isn’t coming straight from HTC and it isn’t related in any way with the already mentioned company. Also, the upgrade, known as the Eternity Custom ROM firmware and based on HTC’s Sense 3.5, is not the Ice Cream Sandwich OS; it’s just an improvement for your old software. Unfortunately, there are no words about the official ICS release for your Thunderbolt 4G handset, therefore this ROM is all you’ll get so far.

So, what I am trying to say is that installing the Sense 3.5 Eternity firmware will make you void the HTC warranty. If somehow something will go wrong (this may happen only if you don’t do all as explained here) or if you will damage the phone software, then you will be on your own. Think twice before starting and if you are not confortable with this aspect maybe it will be better to stop going further. Anyway, read carefully and try to follow my directions.

Now, let’s see the features added once you install the update on your smartphone. I have listed them in the image from below. Check it and see if it’s good enough for you:

Before I begin the proper tutorial, here is what you need to do. First you need to have access to a Windows / Linux / MAC running computer, to your handset and to its USB cord. Then, on the PC and on the phone you must make some preparation operations. I have detailed them during the following lines:

  • In order to apply the OS update you must first root your device. Then you must unlock the bootloader. Only after that you can return here and start installing the Sense 3.5 Eternity on your Thunderbolt 4G.
  • The power left on your smartphone should be at least 70%. If not, I recommend you to charge it first.
  • Then, the process will probably wipe the data out from your handset. So, in case you have something personal saved into its memory, you should backup the HTC data, contacts, messages, apps and everything else you need to. For the backup operation you can use the following tools: SMS Backup + by Jan Berkel for saving the SMS / MMS messages, the android cloud for the contacts and calendar, the Astro File Manager for the Market apps and the SD card, or the PC for any other data stored on your device.
  • Disable the Firewall programs from the computer and from your phone. These apps are usually interrupting the procedure.
  • Enable the USB debugging in your HTC device. For doing this you must go to “Settings -> Applications -> Development -> USB debugging”. The USB debugging can be enabled only when the smartphone is disconnected from the computer.

After completing the above mentioned, you can start updating your device. Read carefully and do as explained in the steps.

How to update HTC Thunderbolt 4G with Sense 3.5 Eternity Custom ROM Firmware

  1. Download the Sense 3.5 Powered Eternity Firmware Zip from here and place it to the computer.
  2. Connect the handset with the PC by using its USB cord.
  3. Copy the files downloaded in step 1 from the PC to your smartphone.
  4. Disconnect the Thunderbolt 4G from the PC by removing its USB cable.
  5. Turn the phone off.
  6. Reboot it by entering in recovery mode. This can be achieved by holding down the Volume Down and the Power Button.
  7. In the recovery mode menu you must select “install zip from sd card” and then “choose zip from sd card”; the file should be right there, just pick it.
  8. The process should take a couple of minutes.
  9. In the end, when you will back on recovery menu, select “++++ Go Back ++++” followed by “reboot system now”.
  10. That’s it.

Now you know how to update the HTC Thunderbolt 4G by manually install the Sense 3.5 Eternity Custom ROM Firmware. In case something isn't working how it should feel free and tell us what went wrong.

chris · 6 years ago

does this root the phone or can i root my phone after installing this firmware?

carlos · 6 years ago

Yes is there a site that I need to go to to down load. I tried school computer and had denied acess.

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