jiffie and WATCHDOG errors could be several reasons and without knowing more details try to disable the following and reboot. Sometimes changing the Kernel will fix this as well or it could be some issue physically.

Go to the Console and enter CTRL + ALT + T then Boot options then select Boot parameters and select all of the 3 options then save and reboot.

If you need more understanding of what ACPI and APM Google is a good source.