Hi guys, I didn't feel like making a new thread but to avoid confusions seems like the best idea. As i mentioned in a previous post I need some help, My boss kidnly asked me if I "could bring some life to his old mac pro 1.1" with some effort and lots of reading I managed to change both cpu for quadcore' 3.0Ghz which pretty much doubled its multicore geekbench score, installed 32GB of ram, added a sata SSD and a radeon 280X, managed to build and install patched boot.efi version of El Capitan, and ran the scripts to protect it in case of "updates" Computer has worked fine for over 6 months, but las week he told me the computer wouldn't boot, fearing he had ****ed something up, I went there with a backup and a copy of the OS, luckily i just did a PRAM reset and the computer booted up fine, he was using it in front of me when it stopped working, video froze, completely unresponsive. I power cycled it and it wasn't booting, so i did a PRAM reset again, and an SMC reset which made the computer boot again, but this time after only a couple minutes it started power cycling on its own. now computer wont chime, at all i get the CPU A CPU B fail light, and have tried resetting everything i know. Removed the big ATI card, and did several combinations of no ram, dimms to see if it was a memory issue. i haven't had any luck with this. at this point i could take the whole thing appart, but I don't know what i'd be looking for, as i said the computer was working and died in front of me. Could i have corrupted the EFI or something like that? i don't expect an easy solution, but maybe someone's got an idea i could try. if you suspect that dissembling and redoing the thermal paste or something like that could fix this, i'll try it out, but kind of doubt it.