Very weird HDMI is not functional in both armbian and multitool: they use very different kernels. Multitool uses the 4.19 vendor kernel, which should be supposed to provide "best" compatibility. The dmesg error is highly related to the missing HDMI, but in a way I can't recognize. About the VFD driver, I guess you're using OpenVFD driver. Latest kernels (both 6.12 and >= 6.16) come with tm16xx driver which is by far much much better and candidate to be upstreamed in the mainline kernel. Here is the github project reference; the driver is already compiled in the kernel, but you may need to edit a device tree overlay by yourself to let it work with your board. To try some debugging, the complete dmesg output and the original device tree of the stock android firmware would be very useful.

Ecco una risposta adeguata per il forum in inglese, considerando il tuo aggiornamento: Hello everyone, I’ve reviewed all the connections carefully using the reference manual to ensure everything is correctly wired. Unfortunately, while the display powers on and stays brightly lit, I still don’t see any output on the screen. Here are a few thoughts and tests I’ve tried: Initialization Problem? I’m unsure if the issue is related to the initialization sequence. I don’t know how to create one tailored to this display. Perhaps this could be due to the fact that it’s an ST7735S, while the driver is designed for the ST7735R? Could this be causing incompatibility issues with the current driver? GPIO Changes: I’ve also experimented with changing the GPIO configurations, specifically: dc-gpios = <&pio 2 6 1>; /* changed the 1 to 0 */ r eset-gpios = <&pio 2 9 1>; /* changed the 1 to 0 */ However, this had no effect. Kernel Compatibility: When I use a kernel version 5.x, the display works correctly. But with the current configuration and the newer kernel, I can’t seem to get it to work. This might be a kernel-level issue, or perhaps something changed in how the driver is initialized. Temporary Workaround: I’ve ordered another display to rule out any potential hardware issues, but it will take a while to arrive. At this point, I’m unsure of how to proceed. If anyone has advice on adapting the driver for ST7735S or creating a compatible initialization sequence, I’d greatly appreciate it. Thanks in advance for your help!

Still not clear why HDMI not working, However VFD display based n FD650 is working. Attached the vfd.conf file for openvfd: clock , USB, ETH,WIFI and COLON working. vfd.conf

Some manufactures change the wifi and lan controllers to keep prices down on new BOM of materials: @WINEDS got experience with thos problems https://forum.armbian.com/topic/28895-efforts-to-develop-firmware-for-h96-max-v56-rk3566-8g64g/page/16/#comment-210825 https://forum.armbian.com/topic/28895-efforts-to-develop-firmware-for-h96-max-v56-rk3566-8g64g/#findComment-217289 https://forum.armbian.com/topic/28895-efforts-to-develop-firmware-for-h96-max-v56-rk3566-8g64g/#findComment-216154

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