Sorry, do not know where to ask regarding PSU warranty. I just sent my PC to a repair shop to replace the PSU (model: RS-400 PSAR-I3, Coolermaster). He say no warranty card but if I got problem with the unit I can go back within 1 year. So how to I check the warranty of the PSU unit or do I need to register the unit? I have receipt from the repair shop for replacing the psu unit.