OK, so I'm typing this from Mint as I worked out that the default selection in GRUB is at the
end of the list rather than the top so by "blindly" pressing
up four times (rather than going
down as I was trying initially) means I can manually make the selection!

So GRUB is definitely there and working - I've now managed to not only change the default selection from Mint to Win7 via editting etc\defaults\grub but have now also worked out the right combination of key presses to make other selections when faced with the blank screen after switching on.
But the question I still have is why the pre-OS video signal might no longer be properly sent/recieved after installing Mint (bios was being displayed normally prior to Mint being installed)...?
Output from Bootinfoscript is below:
- Code: Select all
Boot Info Script 0.61 [1 April 2012]
============================= Boot Info Summary: ===============================
=> Grub2 (v1.99) is installed in the MBR of /dev/sda and looks at sector 1 of
the same hard drive for core.img. core.img is at this location and looks
in partition 72 for .
=> Windows is installed in the MBR of /dev/sdb.
sda1: __________________________________________________________________________
File system: ntfs
Boot sector type: Windows Vista/7: NTFS
Boot sector info: No errors found in the Boot Parameter Block.
Operating System:
Boot files: /bootmgr /Boot/BCD
sda2: __________________________________________________________________________
File system: ntfs
Boot sector type: Windows Vista/7: NTFS
Boot sector info: No errors found in the Boot Parameter Block.
Operating System: Windows 7
Boot files: /Windows/System32/winload.exe
sda3: __________________________________________________________________________
File system: Extended Partition
Boot sector type: -
Boot sector info:
sda5: __________________________________________________________________________
File system: swap
Boot sector type: -
Boot sector info:
sda6: __________________________________________________________________________
File system: ext4
Boot sector type: -
Boot sector info:
Operating System: Linux Mint 14 Nadia
Boot files: /boot/grub/grub.cfg /etc/fstab
sda7: __________________________________________________________________________
File system: ext4
Boot sector type: -
Boot sector info:
Operating System:
Boot files:
sdb1: __________________________________________________________________________
File system: ntfs
Boot sector type: Windows Vista/7: NTFS
Boot sector info: No errors found in the Boot Parameter Block.
Operating System:
Boot files:
============================ Drive/Partition Info: =============================
Drive: sda _____________________________________________________________________
Disk /dev/sda: 60.0 GB, 60022480896 bytes
255 heads, 63 sectors/track, 7297 cylinders, total 117231408 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
Partition Boot Start Sector End Sector # of Sectors Id System
/dev/sda1 * 2,048 206,847 204,800 7 NTFS / exFAT / HPFS
/dev/sda2 206,848 84,459,519 84,252,672 7 NTFS / exFAT / HPFS
/dev/sda3 84,461,566 117,229,567 32,768,002 5 Extended
/dev/sda5 84,461,568 86,413,311 1,951,744 82 Linux swap / Solaris
/dev/sda6 86,415,360 102,037,503 15,622,144 83 Linux
/dev/sda7 102,039,552 117,229,567 15,190,016 83 Linux
Drive: sdb _____________________________________________________________________
Disk /dev/sdb: 128.0 GB, 128035676160 bytes
255 heads, 63 sectors/track, 15566 cylinders, total 250069680 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
Partition Boot Start Sector End Sector # of Sectors Id System
/dev/sdb1 2,048 250,066,943 250,064,896 7 NTFS / exFAT / HPFS
"blkid" output: ________________________________________________________________
Device UUID TYPE LABEL
/dev/sda1 24265DC5265D991E ntfs System Reserved
/dev/sda2 6844607844604B40 ntfs 60GB SSD
/dev/sda5 fb70c39a-3102-4a55-9271-7857e9b93889 swap
/dev/sda6 ec2fcbbb-fef2-40ae-8072-8c157e6f0b8f ext4
/dev/sda7 f6032c8a-28d0-4d95-8ee7-1e32d49c61e7 ext4
/dev/sdb1 86DCD6E5DCD6CE95 ntfs 128GB SSD
================================ Mount points: =================================
Device Mount_Point Type Options
/dev/sda6 / ext4 (rw,errors=remount-ro)
/dev/sda7 /home ext4 (rw)
=========================== sda6/boot/grub/grub.cfg: ===========================
--------------------------------------------------------------------------------
#
# DO NOT EDIT THIS FILE
#
# It is automatically generated by grub-mkconfig using templates
# from /etc/grub.d and settings from /etc/default/grub
#
### BEGIN /etc/grub.d/00_header ###
if [ -s $prefix/grubenv ]; then
set have_grubenv=true
load_env
fi
set default="Windows 7 (loader) (on /dev/sda1)"
if [ x"${feature_menuentry_id}" = xy ]; then
menuentry_id_option="--id"
else
menuentry_id_option=""
fi
export menuentry_id_option
if [ "${prev_saved_entry}" ]; then
set saved_entry="${prev_saved_entry}"
save_env saved_entry
set prev_saved_entry=
save_env prev_saved_entry
set boot_once=true
fi
function savedefault {
if [ -z "${boot_once}" ]; then
saved_entry="${chosen}"
save_env saved_entry
fi
}
function recordfail {
set recordfail=1
if [ -n "${have_grubenv}" ]; then if [ -z "${boot_once}" ]; then save_env recordfail; fi; fi
}
function load_video {
if [ x$feature_all_video_module = xy ]; then
insmod all_video
else
insmod efi_gop
insmod efi_uga
insmod ieee1275_fb
insmod vbe
insmod vga
insmod video_bochs
insmod video_cirrus
fi
}
if [ x$feature_default_font_path = xy ] ; then
font=unicode
else
insmod part_msdos
insmod ext2
set root='hd0,msdos6'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos6 --hint-efi=hd0,msdos6 --hint-baremetal=ahci0,msdos6 ec2fcbbb-fef2-40ae-8072-8c157e6f0b8f
else
search --no-floppy --fs-uuid --set=root ec2fcbbb-fef2-40ae-8072-8c157e6f0b8f
fi
font="/usr/share/grub/unicode.pf2"
fi
if loadfont $font ; then
set gfxmode=2560x1440
load_video
insmod gfxterm
set locale_dir=$prefix/locale
set lang=en_GB
insmod gettext
fi
terminal_output gfxterm
if [ "${recordfail}" = 1 ]; then
set timeout=-1
else
set timeout=10
fi
### END /etc/grub.d/00_header ###
### BEGIN /etc/grub.d/05_debian_theme ###
set menu_color_normal=white/black
set menu_color_highlight=black/light-gray
### END /etc/grub.d/05_debian_theme ###
### BEGIN /etc/grub.d/06_mint_theme ###
set menu_color_normal=white/black
set menu_color_highlight=white/light-gray
### END /etc/grub.d/06_mint_theme ###
### BEGIN /etc/grub.d/10_linux ###
function gfxmode {
set gfxpayload="$1"
if [ "$1" = "keep" ]; then
set vt_handoff=vt.handoff=7
else
set vt_handoff=
fi
}
if [ ${recordfail} != 1 ]; then
if [ -e ${prefix}/gfxblacklist.txt ]; then
if hwmatch ${prefix}/gfxblacklist.txt 3; then
if [ ${match} = 0 ]; then
set linux_gfx_mode=keep
else
set linux_gfx_mode=text
fi
else
set linux_gfx_mode=text
fi
else
set linux_gfx_mode=keep
fi
else
set linux_gfx_mode=text
fi
export linux_gfx_mode
if [ "$linux_gfx_mode" != "text" ]; then load_video; fi
menuentry 'Linux Mint 14 Cinnamon 64-bit, 3.5.0-17-generic (/dev/sda6)' --class linuxmint --class gnu-linux --class gnu --class os {
recordfail
gfxmode $linux_gfx_mode
insmod gzio
insmod part_msdos
insmod ext2
set root='hd0,msdos6'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos6 --hint-efi=hd0,msdos6 --hint-baremetal=ahci0,msdos6 ec2fcbbb-fef2-40ae-8072-8c157e6f0b8f
else
search --no-floppy --fs-uuid --set=root ec2fcbbb-fef2-40ae-8072-8c157e6f0b8f
fi
linux /boot/vmlinuz-3.5.0-17-generic root=UUID=ec2fcbbb-fef2-40ae-8072-8c157e6f0b8f ro quiet splash $vt_handoff
initrd /boot/initrd.img-3.5.0-17-generic
}
menuentry 'Linux Mint 14 Cinnamon 64-bit, 3.5.0-17-generic (/dev/sda6) -- recovery mode' --class linuxmint --class gnu-linux --class gnu --class os {
recordfail
insmod gzio
insmod part_msdos
insmod ext2
set root='hd0,msdos6'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos6 --hint-efi=hd0,msdos6 --hint-baremetal=ahci0,msdos6 ec2fcbbb-fef2-40ae-8072-8c157e6f0b8f
else
search --no-floppy --fs-uuid --set=root ec2fcbbb-fef2-40ae-8072-8c157e6f0b8f
fi
echo 'Loading Linux 3.5.0-17-generic ...'
linux /boot/vmlinuz-3.5.0-17-generic root=UUID=ec2fcbbb-fef2-40ae-8072-8c157e6f0b8f ro recovery nomodeset
echo 'Loading initial ramdisk ...'
initrd /boot/initrd.img-3.5.0-17-generic
}
### END /etc/grub.d/10_linux ###
### BEGIN /etc/grub.d/10_lupin ###
### END /etc/grub.d/10_lupin ###
### BEGIN /etc/grub.d/20_linux_xen ###
### END /etc/grub.d/20_linux_xen ###
### BEGIN /etc/grub.d/20_memtest86+ ###
menuentry "Memory test (memtest86+)" {
insmod part_msdos
insmod ext2
set root='hd0,msdos6'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos6 --hint-efi=hd0,msdos6 --hint-baremetal=ahci0,msdos6 ec2fcbbb-fef2-40ae-8072-8c157e6f0b8f
else
search --no-floppy --fs-uuid --set=root ec2fcbbb-fef2-40ae-8072-8c157e6f0b8f
fi
linux16 /boot/memtest86+.bin
}
menuentry "Memory test (memtest86+, serial console 115200)" {
insmod part_msdos
insmod ext2
set root='hd0,msdos6'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos6 --hint-efi=hd0,msdos6 --hint-baremetal=ahci0,msdos6 ec2fcbbb-fef2-40ae-8072-8c157e6f0b8f
else
search --no-floppy --fs-uuid --set=root ec2fcbbb-fef2-40ae-8072-8c157e6f0b8f
fi
linux16 /boot/memtest86+.bin console=ttyS0,115200n8
}
### END /etc/grub.d/20_memtest86+ ###
### BEGIN /etc/grub.d/30_os-prober ###
menuentry 'Windows 7 (loader) (on /dev/sda1)' --class windows --class os $menuentry_id_option 'osprober-chain-24265DC5265D991E' {
insmod part_msdos
insmod ntfs
set root='hd0,msdos1'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1 24265DC5265D991E
else
search --no-floppy --fs-uuid --set=root 24265DC5265D991E
fi
chainloader +1
}
### END /etc/grub.d/30_os-prober ###
### BEGIN /etc/grub.d/30_uefi-firmware ###
### END /etc/grub.d/30_uefi-firmware ###
### BEGIN /etc/grub.d/40_custom ###
# This file provides an easy way to add custom menu entries. Simply type the
# menu entries you want to add after this comment. Be careful not to change
# the 'exec tail' line above.
### END /etc/grub.d/40_custom ###
### BEGIN /etc/grub.d/41_custom ###
if [ -f ${config_directory}/custom.cfg ]; then
source ${config_directory}/custom.cfg
elif [ -z "${config_directory}" -a -f $prefix/custom.cfg ]; then
source $prefix/custom.cfg;
fi
### END /etc/grub.d/41_custom ###
--------------------------------------------------------------------------------
=============================== sda6/etc/fstab: ================================
--------------------------------------------------------------------------------
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point> <type> <options> <dump> <pass>
proc /proc proc nodev,noexec,nosuid 0 0
# / was on /dev/sda6 during installation
UUID=ec2fcbbb-fef2-40ae-8072-8c157e6f0b8f / ext4 errors=remount-ro 0 1
# /home was on /dev/sda7 during installation
UUID=f6032c8a-28d0-4d95-8ee7-1e32d49c61e7 /home ext4 defaults 0 2
# swap was on /dev/sda5 during installation
UUID=fb70c39a-3102-4a55-9271-7857e9b93889 none swap sw 0 0
--------------------------------------------------------------------------------
=================== sda6: Location of files loaded by Grub: ====================
GiB - GB File Fragment(s)
41.432720184 = 44.488044544 boot/grub/grub.cfg 1
44.829616547 = 48.135434240 boot/initrd.img-3.5.0-17-generic 1
42.392974854 = 45.519110144 boot/vmlinuz-3.5.0-17-generic 1
44.829616547 = 48.135434240 initrd.img 1
44.829616547 = 48.135434240 initrd.img.old 1
42.392974854 = 45.519110144 vmlinuz 1