Mikrotik tile mysteriously rebooting

Hello everyone, I am facing a problem in the last days that has taken me to sleep, I have a CCR1036-12G-4S as a pppoe concentrator with approximately 600 connections and from nowhere it starts to reboot without stopping, I will reset and reconfigures the normal version of Routers 6.42.6 firmware 6.42.6.
What I have already done to solve the problem and so far without results;
I changed the CCR1036 Router, changed the entire power system, replaced the cooling system, put complex passwords, restrict access to the winbox for networks, removed all scripts from / system script, and so far I have not been able to solve this problem.
Has anyone else been through something that might help solve it?

Do you see anything in the logs?