lumia 520 boot repair done but phone still dead


Welcome to Medusa Box Software version 2.5.9
Selected device model: Nokia Lumia 520
Connecting. Please wait…
Checking data…
VREF = 1.82V 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: 4BA00477, IR Length = 4.
Detected TAP ID: 207D00E1, IR Length = 11.
Medusa JTAG Firmware version 1.1.0.
Medusa JTAG Hardware S64 revision C.
JTAG speed : 1000 KHz.
VREF level : 1.82 V
CPU : Qualcomm MSM8227
Core ID : 207D00E1
Storage Device: Samsung eMMC M8G2YC
Device ID : 00150001
Block size : 512 bytes
Blocks : 15269888
Storage size : 7.3 Gb
Opening "C:\Program Files\GsmServer\Medusa\Firmware\NOKIA_LUMIA520_Rep air.mf" file…
Writing BOOT section. Please wait… Done
Disconnected