ONE Beep at startup then all fine...
One beep at startup then all running fine. I went from OS X 10.7 updating one by one 10.8 10.9 10.10 10.11 10.12. Clean installs no additional software added. Currently on Sierra 10.12 ROM 87.0.0.0.0 / SMC 1.68f99 is this right?. I have tested with 4 GB SK Hynix RAM / 8 GB SK Hynix RAM, swapped them around etc, still with one beep. 8 GB RAM is detected in system info & no error codes. Likely the RAM or board is beginning to fail.... Updated to High Sierra 10.13.6 with all available updates and the beep is no longer happening (Restarted 10x).... weird.
I intend to use OCLP to update it to Catalina but worried on the boot ROM / SMC version not being updated to be compatible for OCLP to run smoothly or brick it.
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Review If your Mac beeps during startup
crwdns2934271:0crwdnd2934271:0 Dan crwdne2934271:0