see here for manufacturer's recommendations:
Asus P7P55D EVO Mobo Compatible PC RAM
Might just check you have the memory in the right slots, some motherboards can be a bit fussy especially if it isn't on the approved list or tried just one stick in each slot?
Also check that during your cleaning there were no foreign objects left in the memory slots.
Just curious what you think about this, even though my computer worked with these current OCZ triple channel DDR3 1600 for the past 6.5 years. I now realized that I might've made a mistake. My motherboard is stating that it is dual channel, but the interesting thing those memory sticks worked for that amount of time in a dual channel motherboard. I have cleaned out my computer many times over the past years and never had a problem like this. So it could be that I shocked it with the way I cleaned it. Not sure what your thoughts are about that. also triple channel versus dual channel and normally is it OK to use a triple channel on a dual channel motherboard.
My next question is, if I bought a 8 GB (2 x 4gb) one and I later bought another one of the same kind into the other two slots in the motherboard is that OK? I just don't feel like spending the extra money on a 16 GB one at this time. Also does it have to be the same brand?
Thank you very much for your help.
Is this any help? From an online copy of the manual for your mother board. Asus P7P55D EVO User Manual (Page 43 of 128)
Installing DIMMs that are incompaible with the motherboard may cause system boot
failure, and the DRAM_LED near the MemOK! switch lights continuously. Press and
hold the MemOK! switch until the DRAM_LED starts blinking to begin automatic
memory compatibility tuning for successful boot.
Refer to section 2.8 Onboard LEDs for the exact location of the DRAM_LED.
The DRAM_LED also lights when the DIMM is not properly installed. Turn off the
system and reinstall the DIMM before using the MemOK! function.
The MemOK! switch does not function under Windows
During the tuning process, the system loads and tests failsafe memory settings. It
takes about 30 seconds for the system to test one set of failsafe settings. If the test
fails, the system reboots and test the next set of failsafe settings. The blinking speed
of the DRAM_LED increases, indicating different test processes.
Due to memory tuning requirement, the system automatically reboots when each
timing set is tested. If the installed DIMMs still fail to boot after the whole tuning
process, the DRAM_LED lights continuously. Replace the DIMMs with ones
recommended in the Memory QVL (Qualified Vendors Lists) in this user manual or on
the ASUS website at Access Denied.
If you turn off the computer and replace DIMMs during the tuning process, the system
continues memory tuning after turning on the computer. To stop memory tuning, turn
off the computer and unplug the power cord for about 5–10 seconds.
If your system fail to boot due to BIOS overclocking, press the MemOK! switch to boot
and load BIOS default settings. A messgae will appear during POST reminding you
that the BIOS has been restored to its default settings.
We recommend that you download and update to the latest BIOS version from the
ASUS website at Access Denied after using the MemOK! function
Thank you very much clam1952! I tried all combinations I could with the memory and still can't get it to boot. It looks like I'm have to buy new memory.
What do you think of these choices?
Just letting you all know that I ordered the Kingston hyper X fury 8 GB kit memory. Once I get it and test it I will let you know the results. Thank you again!
I received my memory today and my Computer will still not boot and the memory LED is still lit. So it is my motherboard that is the problem and I am going to call Asus on Monday to see about getting a replacement.
Once I get this new motherboard I'll leave a final post. OK, I appreciate everybody's responses earlier and hope you're having a great weekend.