Raspberry Pi Zero W reboots after sleep hours of ePiframe

[MikeGawi]

On three RPi Zeros (model W, version 1.1) I've tested, one was rebooting automatically after sleep hours of ePiframe. It happened only on Zero version and all were bought in the same shop, same model, used same SD card with the same OS, used same PSU, cable and display. I've spent month on this trying everything (check below) and almost went nuts as nothing helped.

Luckily ePiframe doesn't care about reboots as it is controlled by system-level service that will run frame whenever it is needed and will start just after boot - that device works great as ePiframe and user is not complaing, but yet that problem haunted me.
Unfortunately I had to give the device away and can't test the reason anymore but I thought it would be fair to mention this here.

Usually when Pi keeps rebooting this is A HARDWARE PROBLEM:

• check/change PSU - 99.99999% fault. Display is powered from Raspberry Pi so from my tests I can say that solid 5V 3A power supply is the best also for the displayed photo quality (no shadowing, no shifts, etc.);
• check/change cable that is used for powering Raspberry Pi - common problem so play with different cables;
• use display wires instead of HAT - see here;
• faulty Raspberry Pi - yes it happens. I've seen a lot of this in the Internet so try with different ones;
• try with different SD card - RPi can crash and reboot with corrupted card;
• check and adapt display scripts - I mentioned about this here (at the bottom). There are some issues when display wakes up from deep sleep. Also keep an eye on the Waveshare libraries releases as some other fixes may appear;
• minimize number of running scripts and processes - Zero is slow so if You have something else running, disable it and test again;
• play with over-voltage option - this is my best idea but I haven't tested it with the faulty device. Some say that due to CPU and memory inrush after being idle it may happen that Raspberry Pi will boot by itself. You can check the fault with vgencmd get_throttled;

The things I checked:

• overclocking, RPi temperature monitoring, etc;
• disable Wifi sleep mode, Wifi USB dongles;
• ePiframe code fixing and logs - it rebooted in various phases of ePiframe, not during putting photo on display but even during configuration check;
• system journals, logs, etc - haven't found any useful clues;
• different Raspberry Pi OS versions, not only Lite but Desktop version, clean installed system too. Also I tried with other distributions - no luck

not mentioning hardware and system configuration changes (ZRAM, less RAM for GPU, unistalling everything what was not needed, different SD cards and power units and cables and more and MORE AND MORE), ... that issue was a true pain in the back for me.

I'm open for new hints to fix this permanently so if someone has issue like that (and none of my ideas work) please describe it here, give OS details and let me know how I can help. Or maybe someone had symptoms like that and know how to fix them?

[MikeGawi]

This is a hardware issue that is impacting a specific version of the HAT and the manufacturer acknowledged that there's no software workaround. This issue discuss hardware workarounds that might work