I'm writing this post after spending hours trying to find the answer on which of the many firmware 'main' and 'fs' files I needed myself in order to perform a simcard unlock...
I was sure it wasn't just a matter of looking at the list of e.g. 14 files and reading their titles (or trying to identify what their titles could mean!) but that there was a comparison list or something similar.
The solution to knowing what files you already have installed is by using the program SE_Tool (SE_Tool_2Lite_1.11) and making a list of the software already installed by means of the 'identify' button.
To enable the phone to communicate with the program, you first need to install the usb drivers (see guide in this forum section of 'how to do') and once the phone is communicating with the program, you can move onto this step...
Open the SE_Tool2 Lite program and choose your phone model (in right hand column - top of column) In the example below, I used my k610i phone...
Having taken out your sim card from your phone and replaced the battery (ensuring this is fully charged before starting any work..) Connect the USB cable to your pc but NOT YET into the phone.
Return to the program and on the extreme right hand side navigation buttons - find the 'identify' button.
(hovering over this button with mouse will tell you - "shows phone info, check cable, will NOT HARM phone at all" )
With phone STILL DISCONNECTED - hit the identify button...
The field on LEFT hand side will change and give you the information "Hold 'C' and connect phone"
When you see this, hold the 'C' button on your phone (still turned OFF) and connect the usb cable to the phone - whilst still holding down the 'C' button.
After 2 -3 seconds or so, the information field on the left hand side window will start to write the details of what is inside your phone's program - you can release your finger from the 'C' button as this starts (as it means it has made a connection ;-)
After a few seconds the list will stop writing ... when you see the 'Elapsed time: xx secs" at the bottom of the list - the job is complete and you can press the stop button and disconnect your phone.
Highlight the bottom (or any line) in the list that was generated and right click to copy the list to your clipboard - then paste onto clipboard (and save for future use)
Here is example of what was generated (I have masked the IMEI number for security reasons)...
Welcome to SEtool2 ( LITE edition ) v 1.11
supported DB2010/DB2012 CID49/50/51/52, DB2020 CID49/51/52
Loaded 51 flash descriptors
if you like LITE edition - please visit setool.net/ and buy FULL.
ChipID:9900,EMP protocol:0301
PHONE IS RED RETAIL PRODUCT
FLASH CID detected:52
Speed:921600
Flash ID check:897E
Flash props sent ok
OTP LOCKED:1 CID:51 PAF:1 IMEI:xxxxxxxxxxxxxx CERT:RED
FLASH CID:52 COLOR:RED
Model:K610i
MAPP CXC article: R1JC002 prgCXC1250536_VODAFONE_TH
MAPP CXC version: R1JC002
Language Package:VFE_LIVE_2
CDA article: CDA102497/38
CDA version: R11A
Default article: cxc1250376
Default version: R1JC002
Network LOCKED
Operator: 234-15
Elapsed:12 secs
Now you have this list, you will see that all the relevant information you need to find the correct firmware is listed here....
Phone is - RED RETAIL
CID 52
Phone model is - K610i
Main firmware is R1JC002 using VODAFONE_TH
FS firmware is using VFE_LIVE_2
CDA is CDA102497/38 R11A
and the Network is - LOCKED
I hope that this helps others so that they can quickly identify which firmware they need.
Have a lovely day,
blessings
Seastar
(Say thanks if you found this helpful!)