Loool! Forget Martech!
Use Papuas, my friend!
Leave the phone like it was when you pulled out the battery! Don't do anything before trying this:
1. First of all, try to write a good FLEX into your phone. You can find original C72 flex at my FTP server, go to My Page and you will find a link to FTP server.
username:forum
password:gsmhosting.com
Go in S_gold section, you will find the file with the name "C72_FLEX.rar"
If this method is not working, try method 2
2. You need a FullFlash and U need to work with Papuas like described in this little video!
For best results, use PapuaUtils from my site, is tested with this method and working 100%. After U bring the phone alive again, flash again a Full Flex from method 1!
P.S.: Tell me if it worked for you!