Random Black Lines That Change After Reset

[montea]

Hello, we have this problem, where once the display is powered on, we get thin small black lines appearing in random places on the display. During the whole device operation the black lines seem to stay in the same spot, however after a reset the lines appear somewhere else (the number of black lines would change) or even disappear completely. Everything else seems to look flawless, just these strange artifacts:

[Osman SOYKURT]

Hello @montea ,

That is strange indeed, you can start by checking the memory and see if the framebuffer is filled with what you expect or if it's already corrupted. Then check you display settings, clock, pixel format and see if there's anything related to it. I guess it's a custom board isn't it?

[montea]

Hi @Osman SOYKURT,

Indeed we did check the framebuffer but it seems to be fine. To give some info about our setup, it is a custom board, we use double frame buffer stored in DRAM, MCU is STM32H7 + DRAM MT25QL512ABB1EW9-0SI. 

[montea]

Sorry, the SDRAM used is Alliance AS4C16M16SA-6BIN. In total two such devices on the 32-bit bus for 64 MBytes SDRAM. We are using an SoM EmCraft STM32H7, which has the MCU, Flash and SDRAM on-board.

[Tesla DeLorean]

If you fill the frame buffer with a solid colour does that retain the black lines? If it does it starts suggesting the issue is in the panel.