Check the log , your answer is probably there
Dec 9 20:03:16 miner local1.warn minergate[527]: i2c read word 0x0 0x88 error8
Dec 9 20:03:16 miner local1.warn minergate[527]: INPUT VOLTAGE=0
Dec 9 20:03:16 miner local1.warn minergate[527]: DISCOVERING AC2DC 2
Dec 9 20:03:16 miner user.notice root: /etc/init.d/S99watchdog start
Dec 9 20:03:16 miner local1.warn minergate[527]: STACK:
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(_Z11print_stackv+0x44) [0x36c84]
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(_Z13i2c_read_wordhhPii+0x194) [0x286b8]
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(_Z14ac2dc_init_oneP5AC2DCi+0x54) [0x191dc]
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(_Z10ac2dc_initv+0xbc) [0x194f0]
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(main+0x1d8) [0x2dbc8]
Dec 9 20:03:16 miner local1.warn minergate[527]: /lib/libc.so.6(__libc_start_main+0x110) [0xb6dea040]
Dec 9 20:03:16 miner local1.warn minergate[527]: STACK:
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(_Z11print_stackv+0x44) [0x36c84]
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(_Z13i2c_read_wordhhPii+0x194) [0x286b8]
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(_Z14ac2dc_init_oneP5AC2DCi+0xb0) [0x19238]
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(_Z10ac2dc_initv+0xbc) [0x194f0]
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(main+0x1d8) [0x2dbc8]
Dec 9 20:03:16 miner local1.warn minergate[527]: /lib/libc.so.6(__libc_start_main+0x110) [0xb6dea040]
Dec 9 20:03:16 miner local1.warn minergate[527]: STACK:
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(_Z11print_stackv+0x44) [0x36c84]
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(_Z13i2c_read_wordhhPii+0x194) [0x286b8]
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(_Z14ac2dc_init_oneP5AC2DCi+0x10c) [0x19294]
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(_Z10ac2dc_initv+0xbc) [0x194f0]
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(main+0x1d8) [0x2dbc8]
Dec 9 20:03:16 miner local1.warn minergate[527]: /lib/libc.so.6(__libc_start_main+0x110) [0xb6dea040]
Dec 9 20:03:16 miner local1.warn minergate[527]: UNKNOWN AC2DC
Dec 9 20:03:16 miner local1.warn minergate[527]: STACK:
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(_Z11print_stackv+0x44) [0x36c84]
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(_Z13i2c_read_wordhhPii+0x194) [0x286b8]
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(_Z14ac2dc_init_oneP5AC2DCi+0x1e4) [0x1936c]
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(_Z10ac2dc_initv+0xbc) [0x194f0]
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(main+0x1d8) [0x2dbc8]
Dec 9 20:03:16 miner local1.warn minergate[527]: /lib/libc.so.6(__libc_start_main+0x110) [0xb6dea040]
Dec 9 20:03:16 miner local1.warn minergate[527]: i2c read word 0x0 0x88 error8
Dec 9 20:03:16 miner local1.warn minergate[527]: INPUT VOLTAGE=0
Dec 9 20:03:16 miner local1.warn minergate[527]: DISCOVERING AC2DC 3
Dec 9 20:03:16 miner local1.warn minergate[527]: STACK:
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(_Z11print_stackv+0x44) [0x36c84]
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(_Z13i2c_read_wordhhPii+0x194) [0x286b8]
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(_Z14ac2dc_init_oneP5AC2DCi+0x54) [0x191dc]
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(_Z10ac2dc_initv+0xbc) [0x194f0]
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(main+0x1d8) [0x2dbc8]
Dec 9 20:03:16 miner local1.warn minergate[527]: /lib/libc.so.6(__libc_start_main+0x110) [0xb6dea040]
Dec 9 20:03:16 miner local1.warn minergate[527]: STACK:
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(_Z11print_stackv+0x44) [0x36c84]
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(_Z13i2c_read_wordhhPii+0x194) [0x286b8]
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(_Z14ac2dc_init_oneP5AC2DCi+0xb0) [0x19238]
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(_Z10ac2dc_initv+0xbc) [0x194f0]
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(main+0x1d8) [0x2dbc8]
Dec 9 20:03:16 miner local1.warn minergate[527]: /lib/libc.so.6(__libc_start_main+0x110) [0xb6dea040]
Dec 9 20:03:16 miner local1.warn minergate[527]: STACK:
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(_Z11print_stackv+0x44) [0x36c84]
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(_Z13i2c_read_wordhhPii+0x194) [0x286b8]
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(_Z14ac2dc_init_oneP5AC2DCi+0x10c) [0x19294]
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(_Z10ac2dc_initv+0xbc) [0x194f0]
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(main+0x1d8) [0x2dbc8]
Dec 9 20:03:16 miner local1.warn minergate[527]: /lib/libc.so.6(__libc_start_main+0x110) [0xb6dea040]
Dec 9 20:03:16 miner local1.warn minergate[527]: UNKNOWN AC2DC
Dec 9 20:03:16 miner local1.warn minergate[527]: STACK:
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(_Z11print_stackv+0x44) [0x36c84]
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(_Z13i2c_read_wordhhPii+0x194) [0x286b8]
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(_Z14ac2dc_init_oneP5AC2DCi+0x1e4) [0x1936c]
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(_Z10ac2dc_initv+0xbc) [0x194f0]
Dec 9 20:03:16 miner local1.warn minergate[527]: /usr/local/bin/miner_gate_arm(main+0x1d8) [0x2dbc8]
Dec 9 20:03:16 miner local1.warn minergate[527]: /lib/libc.so.6(__libc_start_main+0x110) [0xb6dea040]
Dec 9 20:03:16 miner local1.warn minergate[527]: i2c read word 0x0 0x88 error8
Dec 9 20:03:16 miner local1.warn minergate[527]: INPUT VOLTAGE=0
Dec 9 20:03:17 miner daemon.info init: starting pid 619, tty '/dev/ttyO0': '/sbin/getty -L ttyO0 115200 vt100 '
Dec 9 20:03:17 miner local1.warn minergate[527]: ----------------------------------
Dec 9 20:03:17 miner local1.warn minergate[527]: --------FET TOP:9 BOT:9---------
Dec 9 20:03:17 miner local1.warn minergate[527]: ----------------------------------
Dec 9 20:03:17 miner local1.warn minergate[527]: DC2DC ignore temp 0
Dec 9 20:03:17 miner local1.warn minergate[527]: DC2DC ignore temp 0
Dec 9 20:03:17 miner local1.warn minergate[527]: Reading DISABLED ASICS
Dec 9 20:03:17 miner local1.warn minergate[527]: vm.userset_fan_level: 100, vm.voltage_start: 670/670/670/670, vm.voltage_end: 740 vm.vtrim_start: ffef/ffef/ffef/ffef, vm.vtrim_end: 10009
Dec 9 20:03:17 miner local1.warn minergate[527]: ------------ FLAG1 = 0x0 -----------
Dec 9 20:03:17 miner local1.warn minergate[527]: Critical: Started!
Dec 9 20:03:17 miner local1.warn minergate[527]: TAKE ONE BOARD 0 PRESENT:1
Dec 9 20:03:17 miner local1.warn minergate[527]: TAKE ONE BOARD 1 PRESENT:1
Dec 9 20:03:17 miner local1.warn minergate[527]: DC2DC stop all
Dec 9 20:03:17 miner local1.warn minergate[527]: DC2DC Init 0 done OK
Dec 9 20:03:17 miner local1.warn minergate[527]: DC2DC Init 1 done OK
Dec 9 20:03:17 miner local1.warn minergate[527]: DC2DC Init 2 done OK
Dec 9 20:03:17 miner local1.warn minergate[527]: DC2DC Init 3 done OK