error to repair boot s5830


Checking data…
VREF = 0.0V is less than required level. Please check target device power supply.
Medusa JTAG Firmware version 1.1.0.
Medusa JTAG Hardware S64 revision C.
Detected TAP ID: 503C10E1, IR Length = 4.
JTAG speed : Auto (RTCK).
VREF level : 2.57 V
CPU : Qualcomm MSM7227T
Core ID : 503C10E1
Flash device: Samsung OneNAND KFG4GH6Q4M
Flash ID : 00EC0050
Page size : 4096 bytes
Block size : 64 pages (256 Kb)
Block count: 2048
Flash size : 512 Mb
Write protection disabled.
Opening "C:\Program Files\GsmServer\Medusa\Firmware\SAMSUNG_GTS5830_Re pair.mf" file…
Writing BOOT section. Please wait…
ERROR[018]: Logical block operation failed at 224 Kb (Hex address 0x00038000). Reason: Connection lost.