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HDMI Shows Flickering Lines, Video Issue? [Solved]

Posted: Tue Jan 23, 2024 5:22 pm
by palito000

Hi, folks. I would gladly appreciate some help here! I recently got a RetroCastle Mister and I'm facing a noise (?) issue with HDMI output.

In video_mode=14 (2560x1440), I get a line of random pixels at the top right corner of the video on the main menu:

299038309-91342ea7-0850-40b0-a404-34e09bd644a5.png
299038309-91342ea7-0850-40b0-a404-34e09bd644a5.png (361.28 KiB) Viewed 1951 times
299039701-e58f6f83-dd56-4b2f-8232-39e92d0cb9ad.png
299039701-e58f6f83-dd56-4b2f-8232-39e92d0cb9ad.png (322.96 KiB) Viewed 1951 times

See video for more details: https://www.youtube.com/watch?v=HfGrDu_kQYM

In video_mode=8 (1920x1080) and Automatic Detection (which defaults to 8 in my screens, I think), I got a different issue. I got random lines of pixels in the wallpaper: https://www.youtube.com/watch?v=SdHMjQsQjy0

I tested multiple HDMI cables, multiple display devices, different power supplies, and the issue persists. I also tested with a clean MiSTer.ini.

The only similar issue I could find was this one: viewtopic.php?t=6185
But the topic doesn't seem to suggest solution other than cleaning the HDMI port, which I already did.

Does anyone have suggestions on how to debug/fix this? Any clues or things I should try? Thanks in advance!


Re: HDMI Shows Flickering Lines, Video Issue? [Solved]

Posted: Tue Jan 23, 2024 7:19 pm
by FPGA64

Mode 14 is technically above what the DE10 is rated to.


Re: HDMI Shows Flickering Lines, Video Issue? [Solved]

Posted: Tue Jan 23, 2024 8:29 pm
by palito000

I see, in video_mode=12 seems I get no flickering issue, or I can't see it.

But in video_mode=8, which is 16:9 like mode 14, I get the other issue: random lines of pixels mid-screen (second youtube link above).

Given that, any clue of what this might be? All issues seem to be related to video_mode and independent of monitors and HDMI cables.
Also: I ran jotego's ram tests sdram48 and sdram96 for about 10 minutes each and both stayed green.

Another issue in modes 8 and 14 is random flickering in PSX core 240ptestsuite main screen. Couldn't find issues with a couple of other roms. Also, I tested 240ptestsuite in SNES core, no issue there as well. Video here: https://youtu.be/IPq36fwi1AU
(edit: this happens on real hw too, so nevermind this: https://github.com/filipalac/240pTestSu ... 1804134202, the other issues remain though)


Re: HDMI Shows Flickering Lines, Video Issue? [Solved]

Posted: Thu Jan 25, 2024 1:44 pm
by palito000

Solved! Changing fb_size to 1/2 resolution solved both issues for me: line of noise in video_mode=14, and random lines in video_mode=8. In fact, in mode 14 there's still a very minimal 1 or 2px noise in main menu, but barely noticible. It definitely gets much worse with fb_size=0.

Therefore, if you're facing any of the problems from my videos in the original post, try fb_size=2.

PS: maybe my issue is the same of this one: https://github.com/MiSTer-devel/Main_MiSTer/issues/482, which remains open.