I need help with my RK27SDK

[THOD]

I changed my firmware, and I think the firmware was wrong. Now the player has black screen and Repair tool doesn't seem to work, it says "Rock USB device not found" or "failed to initialize". I have tried RKusb.tag and FRK.tag. Windows can't find "hidden partition" anymore. What can I do?

THOD-Finland

please help me!!

[THOD]

I have a player like this.
Here is some info:
Product name: RK27SDK
Major version ID: 2.3
Hardware ID: 090114
Chip: RK2706B

I updated my player with RKDM repair tool and now when I hold on/off button it shows white screen, when I don't hold the button its OFF.
I can't see with my PC(cause when I put USB cable to MP4 it goes OFF). How to repair this??