The added line didn't work for me. Here's what did (from: https://wiki.ubuntu.com/HardwareSupportComponentsVideoCardsPoulsboAlternatives)...
Getting 1366x768 resolution
Create file /etc/grub.d/01_915resolution with lines
echo insmod 915resolution
echo 915resolution 58 1366 768 32
and execute:
chmod +x /etc/grub.d/01_915resolution
In file /etc/default/grub, assign value 1366x768x32 to variables GRUB_GFXMODE and GRUB_GFXPAYLOAD_LINUX:
GRUB_GFXMODE=1366x768x32
GRUB_GFXPAYLOAD_LINUX=1366x768x32
Execute:
sudo update-grub
reboot, now you have 1366x768 resolution.
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I already had that resolution, but with the added commands above I can now see the screen too.