Hello everyone! Can you resolve the problem reported? In february , I had 4 equipments with these identical and same problem, some worse than others, and only two barely functioning, others was stopped. They power on normally and suddenly alone they power off , and after that I only can power on again , after hours waiting or only the next day , and when it's power on , on startup , they give me a long beep , before the chime , then I can work for a time (minutes or longtime , it's not secure) . I've sent them to an Apple Authorized Center ,and I had the following diagnostics , have to change the logic board of all and the some have too to change de power supply . And the problem occurred because of electrical problems . All places where I have my equipments (they are in 4 different places, but I but I have tested them in all four locations) , are electrically grounded , the electrical network stabilized , reviewed annually and I use UPS minimum of 1.5 KVA(I have two UPS of 3.75 KVA) . I tested with the original HDD , with all the applications that I use installed , only with the system installed and the same procedure on a new HDD and got the same result . So , it is not electrical problem . I have iMacs , MacBooks , G5 and MacPro early 2009 working in the same places with no problems . I tested all the sites with three different electricians and all approved my Electricnetworks . As I know, all Apple equipment have surge protection, precisely to prevent the components from being damaged by electrical problems.Again , it is not electrical problem . How it's so expensive to do this , until now I'm trying to find cheaper solutions .I've cleaned all parts with products that gives better contact and that protect against the oxidation , some equipments gave me a survival for a while , but presented the problem again . I talked with Apple Computer (from USA) and they do not assume that the problem exists and that many users have the same problem, worldwide. Now I have more 2 equipments and others 4 friends with the same problem , here in my city , and have heard about others owners from here , that already have had the same problem .So , only in my city , more than 20 Mac Pros (early 2008) have had the same problem . If you're not satisfied with the result of Apple, we will have to press them to assume the defect and promote a recall on these equipments. We have many users with the same issue (MacPro off alone) .