What do you mean it's randomly on all boards? Do you mean in all hashboards the error comes up?
Did you already did some basic things to do first before you decided to replace the hashboard?
I suggest flash the unit first with the latest firmware and maybe it is just a software bug. If it does not work try to flash the unit through the SD card.
If it still does not work try to run the unit with only one hashboard and check them one by one if they are working fine there might be an issue with the power supply maybe it can't give enough power to run all hashboards.
However, if the one hashboard is not working as your said then focus on that hashboard if you don't have technical knowledge to repair then you don't have any other choice but to buy a replacement.
You can try contacting Zeusbtc sales on their Whatsapp # +8618623251355 or sales staff email [email protected] they might have a spare hashboard for this unit.