There is a new custom ROM out for the HTC One M7 smartphone with the name MaximusHD. It’s based on the Android 5.0.2 Lollipop software update, but comes with many great features like most good custom ROMs always do. The official Lollipop build is available for most modern-day smartphones, but the latest 5.0.2 firmware is not. Combine that with the M7 being a few years old now with the release date of the HTC One M9 pinned for March 1 and you got yourself a sweet deal with a new custom ROM. Install this one if you want the latest version of Android that probably isn’t coming your way any other way officially any time soon.

Android Lollipop comes with a material design user interface and app drawer, Android Runtime (ART), tap and go for NFC payments, camera updates, security patches which make rooting even harder, Android Beam, a new Easter Egg and more. You’ll get the base of that coming your way with extra feature which change the stock ROM to a custom variant. Those features will be unique to the MaximusHD name and you won’t find the same features working the same way on a different custom ROM.

HTC One M7

Before getting down to the guide we are listing some of the essentials so you don’t make a mistake, you know how to back up and other preparation techniques and you know the risks involved.

  • Do not start until you take a backup of the data. It is a must if you don’t want to lose data. We always wipe the current ROM clean during a custom ROM installation.
  • You must have root access before coming here and starting this guide because it’s not possible to install a custom ROM or firmware unless the system internals are unlocked away from the device manufacture restrictions. Since we know you have the root access already, you can take a Nandroid backup of the ROM after accessing the custom recovery system. It’s always an easy option from the menu inside TWRP or ClockworkMod recovery.
  • A Nandroid backup will take a complete snapshot of the current data, essentially creating a mirror image copy. You’ll end up with your phone contacts, settings, passwords, pictures, music, video and other data all backup up by using the one tool. That said, if you want a different way to store the data you can try out Titanium backup. The Titanium app is available for rooted phones and tablet only from the Google Play store.
  • The MaximusHD ROM is providing users with a stable ROM free of most bugs. It’s reportedly fine to use on your daily phone. You don’t have to install the same on your secondary device, although we understand some people will because they aren’t familiar with the name.
  • You must have the unlocked bootloader on your HTC One M7 with S-Off. You cannot use this guide that’s sorted.
  • You should download the file to the desktop of the computer first; a computer is required to transfer the file over to the phone. it’s always the safest way to install a zip file on a smartphone or tablet. You can look up how to install a custom ROM without a computer but it will just be the same guide without the file transferring to begin with. However, it’s there for a reason so you shouldn’t skip the delegation.
  • You must have the USB Debugging turned on from the Developer Options menu. Find that from the stock Settings menu.
  • The warranty is void after the guide. You can start using the warranty again and take your device in for repairs after going back to stock Android or stock with added bloatware from the carrier networks and device manufacturer.
  • Reserve at least 50% battery power before starting the steps. The USB charging feature will only work for a short while during the guide if you decide to disconnect the phone from the computer.
  • You can use any operating system on the computer for the guide. Choose from Windows PC, Max OS X or Linux machines. There is no program running from the computer you have to install.

How to install the MaximusHD unofficial custom ROM on the HTC One M7 (original flagship)

  1. Download the 5.0.2 unofficial zip file from here.
  2. Choose the desktop for the file location.
  3. Connect the M7 to the computer with the USB cable.
  4. Transfer the zip file to the internal storage of the phone.
  5. Disconnect the M7 from the computer and power down the device.
  6. Reboot it up again in recovery mode, or use the Quick Boot/Reboot manager application for recovery.
  7. Look for the wipe data/factory reset option from inside recovery.
  8. This is the last chance you have to back up the device. Take the Nandroid from the menu before wiping the data.
  9. Select the wipe cache options
  10. Go to the advanced tab and wipe the dalvik cache too!
  11. Go back to the recovery menu and choose to “install zip from SD card”
  12. Upload the MaximusHD Lollipop ROM zip file.
  13. Go back to the main recovery menu and select the reboot system option.
  14. Wait for the device to boot up in normal mode with the new 5.0.2 Lollipop ROM running.

If you are experiencing any problems with the new ROM it’s best to go back in recovery and wipe the cache partition and the dalvik cache once more and reboot. See if that fixes the problem. If not, you want to go in the custom recovery again and do a factory reset. The resets wipe the ROM so taking the backup is vital for your data.