replaced screen now wont boot up

I have just replaced the digitizer on an ipad 4. when I tried to turn it on I got the white apple logo and this message

[nand] _findflashmediaandkeepout :601 physical nand block offset 1

[nand] start:356 this 8x8b397400 PROVIDER=8x8b52db80 flashMedia=8x8b52db80

[nand] WMR_Start : 149 Apple PPN NAND Driver, Read/Write

[nand] WMR_Start : 174 FIL_Init [OK]

[nand] WMR_OPEN : 371 VFL_Open [OK]

[nand] s_cxt_boot:88 sftl: error, unclean shutdown; adopted 641 spares

[nand] WMR_OPEN : 420 FTL_Open [OK]

[nand] _pulbishServices:642 FTL capabilities: 0x00000001

[nand] _ppnvflGetStruct:3469 checking borrowed blocks – count 23 max_count: 23

[nand] _fetchBorrowedList:881 number of borrowed blocks 16

Ive tried rebooting on iTunes in normal recovery and DFU mode, tried a new cable, even tried uninstalling and reinstalling iTunes but get a 4013 error code from iTunes. Now I just get the connect to iTunes symbol with the data cable on he screen even whein its not connected to iTunes.

Ive tried disconnecting the front camera as someone suggested this might be the problem

im stuck, please any more hardware/software suggestions very welcome!

Gemma