Grub Not Displayed on Panasonic HDMI TV

[bungo63]

I would bevery gratefuk for some help with a very weird problems

I have created a dual boot system comprising Windows 10 and Linux Mint 18.

My PC has a an ASUS motherboard with integarted graphic card and is connecetd via the hdmi port and cable to a panasonic plasma TV

When I boot up the PC I do not see the grub menu, but after 10 seconds or so the Linux mint screen appears and all works well.

If i connect my pc to two other tvs in my house (Sony and Samsung) via HDMI I will see the grub menu on boot up.

If i use a VGA connection I will see the grub menu (but not I cannot do this on the Panasonic TV as it doesn't have a VGA port)

So for some reason the grub menu is there ( i assume) but s not being displayed on my HDMI connected Panasonic, but once mint is running it works OK and my display works fine. The problem is that whilst this is happening I cannot see teh grub menu and am unable to select the windows option.

From googling my guess is that there is a default video setting for Grub which is not appropriate for the Panasonic but I do not know how to check this.

One other thing. I am sure that when i first installed Mint all worked correctly. Then I did the updates including the kernel updates and after this i started to have the problems. I could be wrong here as it turned into a late night and i was moving between room in my house to test hings!!

Am i on the right track. Any ideas? Thanks in advance.

[hal8000]

Youre on the right track. Your Panasonic TV does not support your default grub resolution
or refresh rate, or the TV is overscanning and the grub lines are out of viewable region.

Twoi things to try, easiest first:

When booting grub loads the first operating in 10 seconds, so have the TV remote in your
hand and look for a button called P.SIZE or Aspect Ratio, or Zoom (or similar). This may be
all you need to press to resize the screen to see the grub lines. Most TV's will remember the setting.

You can use grub-customizer (not sure if its available in Mint 18. If not edit the settings of /etc/default/grub
with your favourite text editor. Be careful though, as a mistake here and you will end up with a non booting system

***** sample grub below ********

GRUB_DEFAULT="0"
#GRUB_HIDDEN_TIMEOUT="0"
GRUB_HIDDEN_TIMEOUT_QUIET="true"
GRUB_TIMEOUT="8"
GRUB_DISTRIBUTOR="`lsb_release -i -s 2> /dev/null || echo Debian`"
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX=""

# Uncomment to enable BadRAM filtering, modify to suit your needs
# This works with Linux (no patch required) and with any kernel that obtains
# the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...)
#GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef"

# Uncomment to disable graphical terminal (grub-pc only)
#GRUB_TERMINAL="console"

# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo'
GRUB_GFXMODE="1366x768"

# Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux
#GRUB_DISABLE_LINUX_UUID="true"

******** End sample grub *****************


The above is part of my /etc/default/grub. Look at the line in red. It is set to
the default resolution of my laptop. You may need to change this to a resolution
that both your computer and TV can display so you need to google your TV model
number and resolutions it supports.

Backup the file first in case you make a mistable then run

Code: Select all

sudo update-grub

to update the changes. Reboot and see if works. Once again be aware
that if your TV is set to "zoom" it may not look clear so also consult yout TV manual
Hope that helps
.

[bungo63]

Dear hal8000, thank you for replying. I'm just reading your message but its 10pm here and I am being glared at for even thinking of going to "play with the PC" given that it took up most of Saturday night!! So I'll have to wait until tomorrow evening to give your suggestions a go

I'm familiar with the over scan issue as I used to have it in Windows where the edges of the screen would not be visible. That was been fixed by the setting on the TV. My Panasonic is a plasma screen, pretty good image quality for TV but limited in spec (hence no VGA). If memory serves me correct it was an attempt by Panasonic to bring plasma into the mainstream but I think the world was already moving on and developments by Samsung and LG, to name a couple, led them to move out of the market. It was a convenient solution that I inherited (literally) but not optimal. I'd like to buy two dedicated monitors at some point.

[bungo63]

If i do an xrandr command I get the following. Should I use 1280x720 to replace the red text?
My PC is a workstation not a laptop, so this is teh only screen.

Screen 0: minimum 8 x 8, current 1280 x 720, maximum 32767 x 32767
HDMI1 disconnected (normal left inverted right x axis y axis)
HDMI2 connected primary 1280x720+0+0 (normal left inverted right x axis y axis) 698mm x 392mm
1280x720 50.00*+ 60.00 59.94
1920x1080 60.00 50.00 59.94 24.00 23.98
1920x1080i 60.00 50.00 59.94
720x576 50.00
720x576i 50.00
720x480 60.00 59.94
720x480i 60.00 59.94
640x480 60.00 59.94
VGA1 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)

[bungo63]

HI! Plans have changed and I am now able to "play" albeit for a few mins. Found the Aspect button the remote control. It gives me the following options:
Auto, 16:9, 14:9, 4:3, zoom1, zoom2, zoom3. It was on Auto and i have tried all options with no result!

Will now look at grub config files tomorrow.

[bungo63]

Hi there.

First of all I checked my TV model number, its a TX-L32X3B. According to the what hifi review it has a resolution of 1366x768

SO I changed the grub file and run grub update for two different resolutions 1366x768 and 1280x720. I also unchecked the Beep option.

When I reboot i get the beep and then a blank screen for 10 seconds, then its straight into the Mint desktop. My TV displays some messages whilst its doing this to do with the screen auto adapting. My impression from these messages is that the TV is working OK. Its in AUTO mode.

Next stop will be to connect to another TV which does display the GRUB menu and make a windows restore disk and uninstall Mint 18 Cinnamon for maybe another version as see what happens.

[austin.texas]

Try:
GRUB_GFXMODE=1366x768,1280x720,auto

Be sure to do:

Code: Select all

sudo update-grub

after making any change to /etc/default/grub

[bungo63]

Hi Austin Texas.
Thanks for your suggestion. I didn't know that you could put multiple parameters into a line like this. I will give it a go when I get home tonight and report back.

Just for the record I also tried changing
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
to
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash nomodeset"

but this didn't work either, in fact it actually stopped the mint screen being displayed. Fortunately by using a vga connection on another I was still able to see the Grub menu and was able to go into mint and revert the change.

[MajorMuff]

[offtopic] "bevery gratefuk" LOL! [/offtopic]

[bungo63]

Dear Major Muff, I hope I understand you correctly, but yes it was a scary moment when my screen stayed black, and I was pleased to see the grub menu reappear on my VGA connection!

OK, back to Austin Texas, thanks for your suggestion. I tried it it tonight but no luck. The symptoms remain exactly the same.

At the suggestion of a colleague in work, now that I have the grub menu beep working I am able to time hitting the cursor keys which interrupts the timer.
This allowed me to cycle through all my AV inputs in the vain hope that his may "wake up" my hdmi port of the TV - but no joy here either.
Also, in case someone suggests this, I believe that hitting the shift key and then E triggers the grub config file. I've tried doing this blind but the screen remains black so I assume it may be doing this but this too doesn't wake the screen up.

At least now I can cursor down four spaces blind now to get my windows option

[austin.texas]

At least now I can cursor down four spaces blind now to get my windows option

Sorry, I can't help more with the appearance of the Grub menu - BUT, if you can arrow down to start Windows, as you say, you can make that a tiny bit easier with this trick:
Grub Hotkeys
Open /boot/grub/grub.cfg in your text editor:

Code: Select all

gksudo xed /boot/grub/grub.cfg

Go to the ### BEGIN /etc/grub.d/30_os-prober ### section where you will see the first menuentry for Windows.
It will look somewhat like this:

Code: Select all

menuentry "Windows 10 on /dev/sda4"  --class os (and other --classes)

Add "--hotkey=w" so that it looks like this:

Code: Select all

menuentry "Windows 10 on /dev/sda4" --hotkey=w --class os (and other --classes)

Save the file and exit the editor. DO NOT run sudo update-grub, that will erase your edit.
So when it is time to arrow down to Windows, you just hit the "w" key on your keyboard - which is now a "hotkey" to start Windows.

[bungo63]

Cool. I'll give that a try.

I am now thinking of uninstalling mint and rebuilding my windows installation to get everything straight. Then I may install virtual box and try Linux from within that.

Thank you for your help its much appreciated.

[bungo63]

Folks. I think I may have found an explanation for my problem and i suspect there's no solution.

I have now reverted to a single boot windows pc with virtual box. Similar to my GRUB menu problem my PC doesn't let me see the ASUS bios via HDMI - I have to use VGA. I found a bulletin board where an Asus person provided the following explanation:

The issue for you guys not getting a display is a handshaking problem between your GPU and monitor. The only resolution supported by UEFI is 1280X1024. If for some reason your GPU and TV/monitor don't handshake at that resolution, you'll see the splash screen but either get a garbled display or no display in UEFI. You'll also find you're fine when in Windows (for obvious reasons).

There is no fix for this from our side. The GPU VBIOS and monitor native resolution are where the problem lies. If the display you've connected does not handshake correctly with the GPU for whatever reason, it will likely default to its native resolution, and if that's anything other than 1280X1024 you've got a problem displaying UEFI. This happens with some TVs, projectors and monitors with certain GPUs. Older displays are more likely candidates for such problems, as are very high res monitors that use new connections ( DP 1.2 daisy chaining two monitors can create problems) . I suspect a VBIOS update from the GPU vendor might help, but chances of GPU vendors making specific VBIOS versions for this are unlikely. Only workaround is to connect a display that allows you to see UEFI or try using another method of connecting the GPU to the display (DVI instead of HDMI for example). Obviously, the latter is not a guaranteed workaround, as it depends how the display and GPU handshake on that output, too.