Help Sony Xperia SP (C5303) - Bricked when trying to install new ROM

[Mehigh]

Hello,

Recently I've bought a phone from a second-hand seller, the phone has been completely restored with the stock firmware. No problem until now, I've used it for 1 week but as the phone is old (2003), it has been discontinued and abandoned at Android 4.3. After a couple of hours of research I've learnt how to root it, how to install the CWM recovery and install Android 5.1.1 on it. I root the phone, I wipe the Dalvik cache, the data on it, I jump straight into the installation without a SD Card (I put the .zip files on the interal storage) and surprise surprise, the phone won't boot anymore ... At that moment I understood that I rushed the hell out of it without checking if the phone is okay after each installation. I sure broke something in it, and I downloaded the FlashTool for it. I download the stock firmware from the internet, I flash it to the phone [getting System.bin error] (the green light was lit but the screen was off), hopefully now i get the Sony logo for 10 seconds then the phone restarts. It's a step back to life! ... I hope

Mentions:
- When I plug the USB cable into the phone the flashtool will tell me the phone is in Flashmode (I tried to kick it out of that mode, I suceeded, then I get to the logo loop)
- I get system.bin error when trying to flash the stock firmware
- The phone restarts every ~1 minute while in flash mode (green light, no screen on)

I'm seeking for solutions because I literally have no idea what to do from here now ...

Thanks in advance.

 

[Slug]

The first thing I'd suggest is to redownload the firmware file. which should be an .ftf archive, and ensure that the MD5 checksum listed for it matches the completed download. A single corrupt or missing bit will render it useless and prevent it flashing correctly.

Before flashing, ensure the phone is off by removing the back cover and pressing the OFF button below the fixed battery for a few seconds, This forces a shutdown. Open Flashtool, select flashmode and the desired firmware file, then plug in the USB cable and follow the on-screen directions.

 

[Mehigh]

Solved!

I have used an older version of flashtool to flash the ftf file, it worked perfectly this time, I also booted the phone to verify, it works perfectly!

The problem: I used the lastest version of Flashtool.

The solution: Use an older version of flashtool to flash your firmware.