iMac 2011 startup issues & x8 beeps I've a iMac 27" 2011 i7 thats not been used for 2 years, recently plugged back into power and get from what I can make out x8 beeps on pressing power button. Then the iMac sounds like it resets itself and tries to boot again and continues the x8 beeps.

No new ram has been added, I've removed the ram and resetted ram but still get the 8 beeps. I've also powered on with no ram and get the x1 beep signalling no ram installed. 

Could due to the iMac not being used or plugged into power for 2 years, mean the PRAM battery is possibly dead on the logic board?
I like to remove all RAM and then power up just like you did. If there are severe hardware issues - the system often won't give you the correct diagnosis. Now if this works, there still could be hardware issues:


https://support.apple.com/en-us/HT202768


Then I put in one RAM stick and try rebooting. If that doesn't work - reset NVRAM one time (hold for two beep cycles) and then repeat the power off / power on. You've probably done all you can and will actually need to get the hardware repaired or just pieces reconnected internally. The clock batteries aren't needed for successful boot - then you can set the clock as needed - they're nice to have and not required.