SamyGO

If your TV is not CI+, you have to flash required partitions manualy via telnet console. The process is described on wiki or in forum.
If TV is CI+ you need run SamyGO RSA-Disabler before flashing images by hand.
Here is another important information too.

Please write full TV model number from the sticker.

And the firmware version you have upgraded T-CHU7DEUC-3001.1. Is ok, your TV is CI (non plus)

You can now restore the older (3000G?) firmware by flashing mages to TV manualy. I would recomend to restre Your u-boot, but you need right dumps or image files for that. The way for restoring is described here. Its not mandatory, but it is insurance if anything will go wrong with restoring by hand.

I searched for required images for another tv (ue40b8000wv -it has the same fw version as your TV) and i found
this firmware for chinese versions of b7000/8000 TV to download. It has all required images to restore missing partitions. At first You can try to add just u-boot.bin to your upgrade USB for u-boot restoring (its not dangerous), and if you will get u-boot access after, you can try to upgrade again but with Image and fnw.bin on USB - this part is more risky. But remember, you make it on your own risk, because this method hasn`t been tested yet with your TV model...