I have the same problem i can't use my phone and i can't downgrade it.
PM232002 P S WP I
eMMC SMS 14910 MB F-15
MSM8260A v 3.2.1-p1
If i try use RUU.exe phone reboot on 1% and i had error 270
If i try to use Y-connector i have error what my version is higher , or this error DongLeFail:CheckDeviceImage Signature Error.
Can you help me ?