If you have a live CD try using it and boot-repair tool.seems theres nothing wrong with grub but it's good idea to change some boot options. These are some useful options mentioned by canonical itself..
Set your framebuffer resolution to VESA mode xxx. Check here for a list of possible modes.
This parameter disables the whole ACPI system. This may prove very useful, for example, if your computer does not support ACPI or if you think the ACPI implementation might cause some problems (for instance random reboots or system lockups).
Activates the ACPI system even if your computer BIOS date is older than 2000. This parameter overrides acpi=off and can also be used with current hardware if the ACPI support is not activated despite apm=off.
These parameters disable the PCI IRQ routing
This parameter activates the PCI IRQ routing
ACPI is allowed to use PIC interrupts to minimize the common use of IRQs.
ACPI is not allowed to use PIC interrupts.
Deactivates the ACPI system almost completely; only the components required for the boot process will be used.
Deactivates the ACPI system almost completely; only the components required for hyper threading will be used.
Disable the "Advanced Programmable Interrupt Controller (APIC)".
Disable the "local APIC".
Disable the Advanced Power Management.
Changes the way the kernel handles interrupt calls (set it to polling). Can be useful in case of hardware interrupt issues.
- acpi.power_nocheck=1 OR acpi_osi=linux
Disable the check of power state or changes the OS compatibility reported to the BIOS. Necessary on some broken BIOSes to make temperature/fan control work.
refer to this https://help.ubuntu.com/community/BootOptions