[SOLVED] laptop + old VGA monitor= tiles,flicker

[ghorn]

My HP elitebook laptop display broke and I temporarily want to use my old 14" vga monitor as display.
The laptop has a vga port and I hooked it up with my monitor.
I read somewhere that the bios will detect lowest resolution of monitor and adjust accordingly.
But both bios boot screen and the login screen of win 10 has horizontally tiled display and with flicker.
The monitor only supports 1024x768 and i cant change any settings till I see something properly.
I can't even see the bios screen properly.
Any help greatly appreciated

 

[kerberos_20]

hi, your picture shows that its using incorrect display timings, those settings are programmed inside monitor (edid eeprom), it may be that your monitor is missing it (very old monitors did not have it, they used vga/svga etc standarts as base with monitor drivers to add more resolutions), thats before plug and play era (windows 95), after windows 95 monitors with edid pop up, so gpu could read directly what monitor supports
or it may be that your monitor is plug and play (has edid eeprom), but your VGA cable doesnt have required cable connected to pin 15 on vga port
but just by looking at your monitor....i see no buttons..so it belongs to that old CRT category without plug and play support
edit: and it really is, its 9pin VGA monitor SAMTRON SC-428PSL which is 800x600 for today standarts...you can run 1024x768 on those but with 24/30Hz progressive or 60Hz interlaced which is whats causing your issues, and its not advised to run 10244x768 on those modes...it will just cause you eye issues

it can be fixed, but you will need another display source, u got TV around which you can hookup with your laptop?

 

[ghorn]

Thks for a terrific answer. Yes its a 1996 sc-428PS according to the label at the back. Its been very reliable so i just keep it around.
Btw:its possible 1 pin in the connector is missing. Not sure if that affects this connection. The cable works with an equally old desktop -386 but perhaps the driver is handling things there? Would trying a different cable make any diff?
There are adjustment knobs on the monitor -not sure if that is helpful.
I have a TV but don't have a vga-rca converter. I could use the TV too with a converter. However my results using a HDMI-RCA converter (with another stick pc) were not good so I am hesitant to buy a VGA-RCA converter.
But I can get a vga-rca converter if u think that the route to go

 

[TerryLaze]

Shutting off your laptop during boot 3 times, by keeping the power button pressed, will start boot recovery use that to go into safe boot it will use 800x600 resolution and you can run your GPU control panel and adjust new settings.

 

[ghorn]

I got into recovery but that screen is gibberrish so could not proced. However, I am now able to read the bios startup menu using a magnifying glass and fiddling with contrast etc. Also able to boot usb drive - I know boot menu is 6th item and the pen drive shows up 2nd. I got a linux shell. can i force setting via some tool (xrandr on linux?)

 

[kerberos_20]

I got into recovery but that screen is gibberrish so could not proced. However, I am now able to read the bios startup menu using a magnifying glass and fiddling with contrast etc. Also able to boot usb drive - I know boot menu is 6th item and the pen drive shows up 2nd. I got a linux shell. can i force setting via some tool (xrandr on linux?)

it should be possible, i once booted linux with custom edid (as edid on laptop screen got burnt)
xrandr command for changin resolution is
xrandr -s 800x600 -r 60

 

[ghorn]

@kerberos_20: I think xrnadr needs X to be running and I have not yet got there yet. Is there a way to set it in kernel boot or in text mode? I have been searching and I can see resolution can be set but not sure about refresh rate or any other params

 

[TerryLaze]

Do you have an old windows boot CD to try?
You can also try booting with freedos.
If they don't display a clear picture the problem could be with the missing pin and you are just spinning on the same point trying all these things.

 

[ghorn]

@kerberos_20, @TerryLaze - its working. YAY! Thanks for the pointers.
@kerberos_20 that initial pointer on on the monitor being possiblt misread really helped
since it then became just trying to make it use the right setting.
I do think there is a pin missing on the connector but I do know the old 386 has worked with
the same cable.
in the end, I just booted a linux GUI and fiddled with the display setting applet.
The monitor is fine and is sending edid info: the display setting when I could access it was 1024x768 @ 60 and it was listing other modes.

!!! So the problem is that the UEFI firmware is defaulting to 1024x768 and not going lower!!!

This message is from the problem m/c using the old monitor
I tried setting grub to work at 800x600 which would have carried through to kernel but for some reason its not working. Right now uefi, grub, initial os boot is all with the tiles and flicker. After OS boots and during X startup I have added xrandr as startup app to get correct setting.
I now have a working system. Its a shame I cant fix the video in earlier phases. Grub should be able to do it, I just dont know why its not working. Will look at that in a bit.
BTW: not sure if there is way to specify video mode to ÜEFI -I remember reading that they support some kind of scripting
Thanks once again. I can use this for a few weeks and hopefully get back to the regular laptop monitor

 

[kerberos_20]

@kerberos_20, @TerryLaze - its working. YAY! Thanks for the pointers.
@kerberos_20 that initial pointer on on the monitor being possiblt misread really helped
since it then became just trying to make it use the right setting.
I do think there is a pin missing on the connector but I do know the old 386 has worked with
the same cable.
in the end, I just booted a linux GUI and fiddled with the display setting applet.
The monitor is fine and is sending edid info: the display setting when I could access it was 1024x768 @ 60 and it was listing other modes.

!!! So the problem is that the UEFI firmware is defaulting to 1024x768 and not going lower!!!

This message is from the problem m/c using the old monitor
I tried setting grub to work at 800x600 which would have carried through to kernel but for some reason its not working. Right now uefi, grub, initial os boot is all with the tiles and flicker. After OS boots and during X startup I have added xrandr as startup app to get correct setting.
I now have a working system. Its a shame I cant fix the video in earlier phases. Grub should be able to do it, I just dont know why its not working. Will look at that in a bit.
BTW: not sure if there is way to specify video mode to ÜEFI -I remember reading that they support some kind of scripting
Thanks once again. I can use this for a few weeks and hopefully get back to the regular laptop monitor

for grub enter these lines in /etc/default/grub
GRUB_GFXMODE=800x600x32
GRUB_GFXPAYLOAD_LINUX=keep
then run this command:
grub-mkconfig -o /boot/grub/grub.cfg
to make it working

 

[ghorn]

I had set GFXMODE and GFXPAY without success. I then read u first need to switch to graphics mode with TERMINAL_OUTPUT=¨gfxterm¨ but even that has not worked. Will try again in a bit. TKS!