[RK3188] DOOBOL U2 brick - Help plz

[yashiharu]

i got a DOOBOL U2 with 4core + 2gb ram + 8gb rom




After trying to upgrade to kitkat, it bricked ...

on WinXP, rockchip usb driver V3.5 installed, work well.
used RKBatchTool v1.7, work well.
Successfully restore by those kitkat roms, the device doesn't turn off, i have to pull the otg power to turn it off.
After I powered it with 5V usb, the power LED on, but nothing show on screen(HDMI cable is OK)

I have tried the following roms:
1) CR11S-Tech1-CS968-2MP-4.4KitKat-Ultra-Multi-Media-Super-ROM-AP6210-20140704_update
2) DOOBOL-U2-V0.1-8188-0924
3) update_mk918_100k4100_beta0.1
4) finless_kitkat_1080_kernels (can not be load at all)
5) RKM MK902_4.4.2_20140515
6) DOOBOL-U2-V0.1-MTK-0924

none of them works.

Please advise, how to rescue it? (even back to 4.2)
thx

[yashiharu]

today:

1) short pin 8 & 9 on the NANO - enter MaskRom mode
2) use ROM Flash tool 137 to erase NANO (fineless loader 1.20) - success!
3) use RKBatchTool 1.7 to restore DOOBOL-U2-V0.1-MTK-0924 - success!

result:
still nothing on TV ...

[duventj]

Hello yashiharu,

I've got the same device.
I can send you my dump if it can help

Best regards