Maintenance of the main model series: GALAXY S4 series GALAXY SIII series GALAXY Note2 GALAXY SII series Galaxy Trend Duos series Galaxy Grand Series GALAXY NOTE series Galaxy nexus series GALAXY Premier Series Nexus S series. DIY Brush fault freedom appears as: i9300 n7100 brush machine fails to boot fixed screen restart, no baseband, there is a network lock, signal prohibit other maintenance. Common chip-level repair failure cases such as: Samsung i9300 i9220 n7100 n7000 i9100g i9003 i9000, which do not boot repair, jtag repair for CPU swap hard character, power chips, baseband chipset, touch chipset, signal problems such as power amplifiers and other signal maintenance.