I have a computer that I have recently built using an:ASUS M4A88T-M MOTHERBOARD,AMD PHENOM 2 multi-core processor,500W Eagle Voltas PSU,and I dont know if this helpful information but a Sector 5 Patriot DDR3 4GB MEMORY.After building the computer,I attempted to turn it on but everything in the computer(LED's,fans,ect.) Just turned off immediatly so I loosened the motherboard and it turned on but nothing at all appeared on the screen appeared so I refered to the motherboard manual and an LED next to the ram was lighting witch mean an it checked the DRAM in sequece during motherboard booting process and will light until problem is solved.Could this be a problem with incompatible DIMM's?

It's possible that it's a ram incompatability. It's also possible that the PSU isn't up to the job as the AMD Phenom's are rather power hungry beasts. Are you also using a power hungry graphics card?

Iam not using a graphics card because the motherboard came with both a VGA and HDMI port.If this is a problem because of how much power the AMD Phenom is using,should I replace the CPU or the PSU and if the PSU,how many Watts?I'm going to CompUSA soon to return my RAM,any suggestions about what kind of DDR3 RAM to get?(Kingston,ASINT,Samsung,ect.)

I have used Hynix ram with quite a few Asus boards without problems if that's any help! Make sure the ram you get is non-ecc. The board's manual should give you information about what wattage of PSU they recommend.