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Black Screen on Startup Help
Posted: Tue May 11, 2021 1:23 pm
by AndyGarton
Hi all, I've managed to mess up my screen settings somehow, while trying to set up a new monitor. I get a black screen after the AmigaOS 4.1 loading screen. The machine is responsive (I can reboot it using Ctrl-A-A). I've tried booting with no startup sequence and deleting screenmode.prefs, but it makes no difference. From memory, the last thing I did was select the "auto-detect monitor" option in the screen mode preferences.
Help!
Re: Black Screen on Startup Help
Posted: Tue May 11, 2021 1:51 pm
by AndyGarton
Well, I seem to have sorted it, but not entirely sure why - on a long-forgotten-instinct, I tried copying the contents of Storage/Monitors to Devs/Monitors, and that let me boot into a low res mode, from which I was (eventually) able to select my desired native resolution mode.
Re: Black Screen on Startup Help
Posted: Tue May 11, 2021 2:09 pm
by Raziel
You have been bitten by an infamous screenmode prefs bug, where it saves an incorrect Hz to the monitor file and f*** up booting.
See
here and
here
Not sure when or if ever this will get fixed...
Re: Black Screen on Startup Help
Posted: Tue May 11, 2021 4:11 pm
by nbache
@Raziel:
I just quickly read through all four pages of the first thread you link to (the one here on this forum).
I am not sure what the exact bug would be, out of all the problems mentioned in the thread.
Can you explain what you'd think should be fixed (in OS4), so I can make a report about it?
Best regards,
Niels
Re: Black Screen on Startup Help
Posted: Wed May 12, 2021 9:28 am
by Raziel
@nbache
Well, it's a long time, but i try to be brief
Screenmode prefs "incorrectly" reports it as 57Hz and all the 60Hz modes as 61Hz so i see a bug in the prefs program.
Try to manually change your setting to 55 Hz, reboot, see if that works and move up to the closet setting that works for you.
If you do change your monitor file manually, reboot and go back to the Screenmode prefs
it will always change your Hz setting (the one after the @) back to at least 60, on saving killing your painstakingly found setting that works.
"Detect Settings Automatically" will not work in his case since the Prefs and/or the driver sets the Frequency "automatically" to @60 for 2560x1440 again, which will result in the same "Out of Range" error.
DDCMODE=All just takes every resolution (like you said) that is reported by the monitor.
Since most "modern" monitors (at least that is what my BenQ does) nowadays would rather let hell freeze over before using/reporting resolutions with a lower frequency than 60 Hz i doubt that @simulant's monitor will.
So, tldr
1) Screenmode prefs refuses to take any (manual) Hz settings below 60 into account and changes it once the prefs are saved
2) Screenmode prefs does not obey the max/min HSync/VSync setting and suggest (and saves) resolutions that
will be out of range
If more information is needed i think i can find the time to redo most of what i wrote in those threads...too bad it wasn't picked up as bug back when i wrote it
Re: Black Screen on Startup Help
Posted: Wed May 12, 2021 8:14 pm
by nbache
What is the version of Prefs/ScreenMode we are discussing here?
53.24?
I have a feeling these might be some issues fixed in later versions, of which the latest in beta is currently 53.27.
I have no idea why that wasn't included in Update 2, though, but I assume there is some relation to other modules which couldn't be released at that time.
I'll try to find out.
Best regards,
Niels
Re: Black Screen on Startup Help
Posted: Thu May 13, 2021 12:50 pm
by Raziel
53.27 (14.08.2017)
Re: Black Screen on Startup Help
Posted: Thu May 13, 2021 1:24 pm
by nbache
Oh, so it was actually released with Update 2? Strange. I'll have to check again on my Public Test partition.
Best regards,
Niels
Re: Black Screen on Startup Help
Posted: Thu May 13, 2021 9:25 pm
by Raziel
@nbache
Yep
ScreenMode v53.27
UPDATED
o Changed the minimum VSync rate to 30 Hz in the "Monitors" tab
o During loading a monitors tooltypes, a check was made for minimum
VSync values of less than 60. This has now been lowered to 30 to
better suit 4K modes.
o Cleaned out some legacy code.
FIXED
o AVT_Clear, which is just an alias for AVT_ClearWithValue, was
incorrectly used in some places with TRUE in the data portion of
the tag (causing the memory to be filled with 0x01 rather than
being cleared to zero).
And it seems the two problems i was pointing at were fixed...
Re: Black Screen on Startup Help
Posted: Thu May 13, 2021 11:28 pm
by nbache
Yep, I also saw it on my public update test partitions when I checked again, don't know what went wrong the first time I checked (maybe I checked another partition by mistake, I have almost 20 boot partitions/configs on the X1000 alone

).
So at least those fixes are out there. But are there other issues we need to investigate?
Best regards,
Niels