lumia 900 unlock problem

Resetting and Exploring JTAG chain…OK
Halting Core…OK
Initializing Device…OK
Detecting ONFI #1 ID…MICRON MT29F1G08ABBDAH4, 128 MiB
Sending Flash Loader…OK (73135 Op/Sec)
Retrieving Unlock Codes…Flash Read Error at 0x05F90000, Bad Answer from Loader 0x0, 0x3C03
Waiting for Device Connection 20 second(s)…OK
Resetting and Exploring JTAG chain…OK
Halting Core…Retry
Resetting and Exploring JTAG chain…OK
Halting Core…OK
Initializing Device…OK
Detecting ONFI #1 ID…MICRON MT29F1G08ABBDAH4, 128 MiB
Sending Flash Loader…OK (73233 Op/Sec)
Retrieving Unlock Codes…Flash Read Error at 0x05F90000, Checksum Error in Loader Answer
Waiting for Device Connection 20 second(s)…OK
Resetting and Exploring JTAG chain…OK
Halting Core…Retry
Resetting and Exploring JTAG chain…OK
Halting Core…OK
Initializing Device…OK
Detecting ONFI #1 ID…MICRON MT29F1G08ABBDAH4, 128 MiB
Sending Flash Loader…OK (73670 Op/Sec)
Retrieving Unlock Codes…Flash Read Error at 0x05F90000, Bad Answer from Loader 0x0, 0x4703

pls help