Machine normal control parts, main shaft turn, first check the main shaft drive circuit, found that the main shaft drive power supply IC 1002 (UN102) {11} only 1 foot. 4 v. Disconnect the insurance tube triode type BX1008 measured again (N25), the recovery of normal 4 feet voltage v. Check insurance tube BX1008 and other peripheral circuit element, not found the problem, so doubt linked to BX1008 main shaft driver module IC 2005 (BA6430S) internal damage, replace IC 2005 module, machine back to normal.SX2service manual download site