Flashing SE T637

I've now collected all of the files for flashing to the new firmware and unbranding my Sony Ericsson T637. Things seem to be a little easier than I had once imagined. This entire process is in no way illegal. I hope that this tutorial will help others in my situation who are curious as to how things work. As always, if you are unsure about how to do any of the steps that I mention, don't break you're phone. I cannot be held liable for any damage done to your phone with the steps listed below. There are many online businesses and local shops that specialize in doing this exact procedure. Also, of important note, if your phone is within the manufacturer's warantee date, they will upgrade the firmware for you. In the case of a Sony Ericsson phone, their warantee lasts 15 months from the date printed on the ID label of the phone. The date is in the format MMwWW where MM is the two digit month and WW is the two digit week number. If your phone is out of warantee, Sony is much more expensive than other reputable online flashers. Here's the breakdown on what is needed in practically any do-it-yourself upgrades:

• Software that can actually flash the phone. ie DIV or SEtool
• A cable. I'll be trying to use a T28 cable that are in abundence on eBay.
• Update since original posting: The T28 worked perfectly for those just interested in unbranding/unlocking their phones. BUT the T28 is incapable of upgrading the phone's ARM file and because of this, if you are wanting to flash your firmware, you need a DSS-20/25. The AVR and the ARM must match in version to work.
  
• The flash files. I can't distribute these for legal reasons.
• AVR and ARM - These files are what runs the phone. If you want to upgrade your phone to a newer (or older?) flash version, then both of these files are required and both of them must be of the same version.
• GDFS - This file is used by the carrier to personalize the phone. They load this with proprietary information that customizes it to their liking. There are original GDFS files available that can overwrite the carriers. This is what will 'unbrand' your phone.
• A computer. Nothing interesting here. Depending on if you use my method or another, you may need special ports. My procedure calls for a serial (9 pin) port for my cable, others need USB or an LPT Parrallel port.

When updating the GDFS, other pertinate information my be overwritten. Including the IMEI number, etc. It is illegal in most countries to change this, so you should always set it back to what it was originally when attempting to flash your own phone.

• Update since original posting: In my experience, the new GDFS did not overwrite my old IMEI, but always check. My new GDFS did give me new games, ringtones, and wallpapers, however. =)
  

I'm currently waiting on my cable to come in the mail, but as soon as it arrives, you can bet that I'll be trying my method and updating this accordingly.

Thanks to Cellular Support for all their help with this issue.