Hi all, I have a July 2008 mac pro which seems to have a problem with the Psu. When i press the power button it starts and after some seconds before it logs into OS it shuts down. Sometimes it starts successfully and it might work without problems or it might shutdown during operation. As i read to some forums many owners of the 2008 model experience such problem and those who changed the PSU solved the problem. Now, because of the days apple wants to keep my Mac for checking is forbitten for my work, I want to change the PSU myself. So, which is the PSU i have to purchase in order to be compatible? Does it have a specific number i must check before purchasing a new one? Any details or suggestions are welcome!!! Thanks!