3,4 error

I Have a Precision T7500 workstation that has a particoular issue, it reboots several times, around 10/15 before getting on boot screen. The power Button is Green, and also the 3 and 4 indicatore are Green. From the manual i find that it can be a RAM issue, so i tryed to remove them all and insert only one of that a time to see which of the RAM have some fault. I did't find which of them have errors because all have the same behaviour. I also tryed to change RAM SLOT, but without any solution. I'm writing to you with this machine, after 10/15 reboots. Do you have the same error? Or Do you have any idea how to fix it?

Thanks a lot.