Here is the T-mobile Optimus F6 (LG D500BK) Official Stock Rom / Firmware Revision “D50010b_01”.
You can flash this Stock ROM to unbrick or unroot your T-mobile Optimus F6 (LG D500BK) smartphone.
IMEI:0136580033*****
Model:LGD500BK
Suffix:ATMOOP
Buyer:TMO
Software Version:D50010H_00
OS Version:JB
File Name:D50010h_00.kdz
KDZ File size:756134785
http://dl02.gdms.lge.com:5006/dn/downloader.dev?fileKey=FW992785432109876543213/D50010h_00.kdz
You can also use the LG MOBILE SUPPORT TOOLS from LG official to recover your device if you bricked your Optimus F6.
Click here for further instructions ON XDA forum [TUTORIAL] update firmware through flashing the kdz files