RAM is not detected when installed
I'm looking for a few tips or advise, my mid- 2010 27" iMac 11,3 Core i7 2.93 is not recognizing installed RAM. I’m getting the error code 1 beep every 5 seconds. The diagnostic LED’s 1 and 2 are lighting up but the RAM error beep continues.
Other than new RAM or a bad/damaged logic board what could cause this error? Any other possibilities such as wiring? More details below.
Note: It did boot from an external drive before I started the repairs and upgrades with no issues.
The original 1TB drive, not surprisingly died after six years of faithful service, so I decided to repair and upgrade to an OWC supplied 4TB HGST spinner hard drive w/ OWC thermal sensor, OWC SSD & dual drive kit, and a CMOS battery.
I also replaced the Super Drive with a Blu-ray.
The upgrade went smoothly with the exception of the iMac claiming there's no RAM installed by the beeping error sound. I did use an antistatic wrist strap and antistatic mat when I removed the logic board.
One thing in the behavior after I finished assembling it that may not even make a difference, is that it attempted to power on before I even hit the power switch. I heard the usual signs of life, a fan moves a little air, the optical drive checks for a disc and the spinning hard drive makes it's typical sound then the error tones begin. The screen remains black and the one time I tried the PRAM reset it took a few seconds longer before the error tones started.
Here’s what I’ve tried so far with no changes:
PRAM & SMC reset, no change.
Cleaned the old OWC ram 4X4 GB and the slots with compressed air, swapped and rearranged all four 4GB OWC ram modules one at a time into each slot turning it on each time with the same error.
Bought new ram, installed, swapped slots, same error, no change.
Tried the MacBook Pro no ram tip, no change.
Is this a good question?