You most likely are hard bricked, but you still have a slight chance to get into download mode. Not sure how you managed a brick by restoring a backup, but I'll try to help.
Ok, you are going to need the drivers for your phone.
http://www.mediafire.com/file/6onrjbyd46j4lhj/T-Mobile_t989_GSII_ADB_Drivers.zip
You need odin as well, download it.
http://www.mediafire.com/?u868rqz4qn0ta34
These links were provided by KonstantinKeller
Go here
http://www.sammobile.com/firmware/ and make an account. I use sammobile because it contains everything in one shot. No need to get radio and crap from other places. After you make an account go to firmware section and type t989 in the search box. download the t989uvkid. ASSUMING YOU HAVE AMERICAN T989
After you have completed the download you are going to need to unzip it with 7zip to extract the tar.
Plug the USB cable into your computer, without plugging it into your phone.
Hold VOL UP + VOL DOWN while plugging in the USB cable to your phone. Stop holding buttons when the ''Warning'' appears.
Press Volume UP and start ODIN (Run as Admin on Vista and 7, just to be safe)
Click PDA and locate the MD5 file you extracted earlier.
WAIT FOR ODIN TO RECOGNIZE YOUR PHONE. THE COM PORT WILL TURN YELLOW AND HAVE A NUMBER
MAKE SURE NOTHING BUT AUTO REBOOT IS CHECKED!!!!!!!
Press 'Start' and be patient. It will take a few minutes because it is a large file.
phone will reboot automatically.
If you can't get the phone to be recognized try different usb ports or a different computer if you have another. This may not work at all, considering it sounds like you are hard bricked. Good luck!