same computer but now getting also unwanted power off
3.16.0-37-generic 
kernel.log not showing any errors
but Xorg.0.log is showing

(EE) [mi] EQ overflowing.  Additional events will be discarded until existing events are processed.
(EE) 
(EE) Backtrace:
(EE) 0: /usr/bin/X (xorg_backtrace+0x48) [0x7f9a6d427ed8]
(EE) 1: /usr/bin/X (mieqEnqueue+0x22b) [0x7f9a6d409d3b]
(EE) 2: /usr/bin/X (QueuePointerEvents+0x52) [0x7f9a6d2ed5e2]
(EE) 3: /usr/lib/xorg/modules/input/evdev_drv.so (0x7f9a644bc000+0x5fae) [0x7f9a644c1fae]
(EE) 4: /usr/lib/xorg/modules/input/evdev_drv.so (0x7f9a644bc000+0x6465) [0x7f9a644c2465]
(EE) 5: /usr/bin/X (0x7f9a6d283000+0x90ae8) [0x7f9a6d313ae8]
(EE) 6: /usr/bin/X (0x7f9a6d283000+0xb9cb0) [0x7f9a6d33ccb0]
(EE) 7: /lib/x86_64-linux-gnu/libc.so.6 (0x7f9a6b403000+0x36d40) [0x7f9a6b439d40]
(EE) 8: /usr/lib/x86_64-linux-gnu/xorg/extra-modules/nvidia_drv.so (0x7f9a659fb000+0x9ef42) [0x7f9a65a99f42]
(EE) 9: /usr/lib/x86_64-linux-gnu/xorg/extra-modules/nvidia_drv.so (0x7f9a659fb000+0xa0194) [0x7f9a65a9b194]
(EE) 10: /usr/lib/x86_64-linux-gnu/xorg/extra-modules/nvidia_drv.so (0x7f9a659fb000+0x1225f3) [0x7f9a65b1d5f3]
(EE) 11: /usr/lib/x86_64-linux-gnu/xorg/extra-modules/nvidia_drv.so (0x7f9a659fb000+0x6a9068) [0x7f9a660a4068]
(EE) 12: /usr/bin/X (0x7f9a6d283000+0x195b93) [0x7f9a6d418b93]
(EE) 13: /usr/bin/X (0x7f9a6d283000+0xdf4d5) [0x7f9a6d3624d5]
(EE) 14: /usr/bin/X (0x7f9a6d283000+0xee25c) [0x7f9a6d37125c]
(EE) 15: /usr/bin/X (0x7f9a6d283000+0xef298) [0x7f9a6d372298]
(EE) 16: /usr/bin/X (0x7f9a6d283000+0x5369e) [0x7f9a6d2d669e]
(EE) 17: /usr/bin/X (0x7f9a6d283000+0x574ea) [0x7f9a6d2da4ea]
(EE) 18: /lib/x86_64-linux-gnu/libc.so.6 (__libc_start_main+0xf5) [0x7f9a6b424ec5]
(EE) 19: /usr/bin/X (0x7f9a6d283000+0x42a5e) [0x7f9a6d2c5a5e]
(EE) 
(EE) [mi] These backtraces from mieqEnqueue may point to a culprit higher up the stack.
(EE) [mi] mieq is *NOT* the cause.  It is a victim.
(EE) [mi] EQ overflow continuing.  100 events have been dropped.
(EE) 
(EE) Backtrace:
(EE) 0: /usr/bin/X (xorg_backtrace+0x48) [0x7f9a6d427ed8]
(EE) 1: /usr/bin/X (QueuePointerEvents+0x52) [0x7f9a6d2ed5e2]
(EE) 2: /usr/lib/xorg/modules/input/evdev_drv.so (0x7f9a644bc000+0x5fae) [0x7f9a644c1fae]
(EE) 3: /usr/lib/xorg/modules/input/evdev_drv.so (0x7f9a644bc000+0x6465) [0x7f9a644c2465]
(EE) 4: /usr/bin/X (0x7f9a6d283000+0x90ae8) [0x7f9a6d313ae8]
(EE) 5: /usr/bin/X (0x7f9a6d283000+0xb9cb0) [0x7f9a6d33ccb0]
(EE) 6: /lib/x86_64-linux-gnu/libc.so.6 (0x7f9a6b403000+0x36d40) [0x7f9a6b439d40]
(EE) 7: /usr/lib/x86_64-linux-gnu/xorg/extra-modules/nvidia_drv.so (0x7f9a659fb000+0x9ef42) [0x7f9a65a99f42]
(EE) 8: /usr/lib/x86_64-linux-gnu/xorg/extra-modules/nvidia_drv.so (0x7f9a659fb000+0xa0194) [0x7f9a65a9b194]
(EE) 9: /usr/lib/x86_64-linux-gnu/xorg/extra-modules/nvidia_drv.so (0x7f9a659fb000+0x1225f3) [0x7f9a65b1d5f3]
(EE) 10: /usr/lib/x86_64-linux-gnu/xorg/extra-modules/nvidia_drv.so (0x7f9a659fb000+0x6a9068) [0x7f9a660a4068]
(EE) 11: /usr/bin/X (0x7f9a6d283000+0x195b93) [0x7f9a6d418b93]
(EE) 12: /usr/bin/X (0x7f9a6d283000+0xdf4d5) [0x7f9a6d3624d5]
(EE) 13: /usr/bin/X (0x7f9a6d283000+0xee25c) [0x7f9a6d37125c]
(EE) 14: /usr/bin/X (0x7f9a6d283000+0xef298) [0x7f9a6d372298]
(EE) 15: /usr/bin/X (0x7f9a6d283000+0x5369e) [0x7f9a6d2d669e]
(EE) 16: /usr/bin/X (0x7f9a6d283000+0x574ea) [0x7f9a6d2da4ea]
(EE) 17: /lib/x86_64-linux-gnu/libc.so.6 (__libc_start_main+0xf5) [0x7f9a6b424ec5]
(EE) 18: /usr/bin/X (0x7f9a6d283000+0x42a5e) [0x7f9a6d2c5a5e]
(EE) 
(EE) [mi] EQ overflow continuing.  200 events have been dropped.
(EE) 
(EE) Backtrace:
(EE) 0: /usr/bin/X (xorg_backtrace+0x48) [0x7f9a6d427ed8]
(EE) 1: /usr/bin/X (QueuePointerEvents+0x52) [0x7f9a6d2ed5e2]
(EE) 2: /usr/lib/xorg/modules/input/evdev_drv.so (0x7f9a644bc000+0x5fae) [0x7f9a644c1fae]
(EE) 3: /usr/lib/xorg/modules/input/evdev_drv.so (0x7f9a644bc000+0x6465) [0x7f9a644c2465]
(EE) 4: /usr/bin/X (0x7f9a6d283000+0x90ae8) [0x7f9a6d313ae8]
(EE) 5: /usr/bin/X (0x7f9a6d283000+0xb9cb0) [0x7f9a6d33ccb0]
(EE) 6: /lib/x86_64-linux-gnu/libc.so.6 (0x7f9a6b403000+0x36d40) [0x7f9a6b439d40]
(EE) 7: /usr/lib/x86_64-linux-gnu/xorg/extra-modules/nvidia_drv.so (0x7f9a659fb000+0x9ef42) [0x7f9a65a99f42]
(EE) 8: /usr/lib/x86_64-linux-gnu/xorg/extra-modules/nvidia_drv.so (0x7f9a659fb000+0xeeb79) [0x7f9a65ae9b79]
(EE) 9: /usr/lib/x86_64-linux-gnu/xorg/extra-modules/nvidia_drv.so (0x7f9a659fb000+0xeef12) [0x7f9a65ae9f12]
(EE) 10: /usr/lib/x86_64-linux-gnu/xorg/extra-modules/nvidia_drv.so (0x7f9a659fb000+0xef510) [0x7f9a65aea510]
(EE) 11: /usr/lib/x86_64-linux-gnu/xorg/extra-modules/nvidia_drv.so (0x7f9a659fb000+0xa011b) [0x7f9a65a9b11b]
(EE) 12: /usr/lib/x86_64-linux-gnu/xorg/extra-modules/nvidia_drv.so (0x7f9a659fb000+0x1225f3) [0x7f9a65b1d5f3]
(EE) 13: /usr/lib/x86_64-linux-gnu/xorg/extra-modules/nvidia_drv.so (0x7f9a659fb000+0x6a9068) [0x7f9a660a4068]
(EE) 14: /usr/bin/X (0x7f9a6d283000+0x195b93) [0x7f9a6d418b93]
(EE) 15: /usr/bin/X (0x7f9a6d283000+0xdf4d5) [0x7f9a6d3624d5]
(EE) 16: /usr/bin/X (0x7f9a6d283000+0xee25c) [0x7f9a6d37125c]
(EE) 17: /usr/bin/X (0x7f9a6d283000+0xef298) [0x7f9a6d372298]
(EE) 18: /usr/bin/X (0x7f9a6d283000+0x5369e) [0x7f9a6d2d669e]
(EE) 19: /usr/bin/X (0x7f9a6d283000+0x574ea) [0x7f9a6d2da4ea]
(EE) 20: /lib/x86_64-linux-gnu/libc.so.6 (__libc_start_main+0xf5) [0x7f9a6b424ec5]
(EE) 21: /usr/bin/X (0x7f9a6d283000+0x42a5e) [0x7f9a6d2c5a5e]
(EE)