I have tried all sorts of key sequences and nothing works. I don't hear the startup sound or see any screen changes. If I eject the memory then restart the iMac I hear a beep. When putting it back in it doesn't work. If I unplug then plug in while holding the power button the fans come on really loud.
Any help would be greatly appreciated.
Thanks,
Randy
iMac 27″, macOS 10.15
The last thing I can offer before declaring it dead is connecting with a wired keyboard and ensuring it is shut down. Then unplug power from the back of the computer for about 5 minutes. Then plug it back in, then hold down the power button for about 15 seconds.
If it still will not start it sounds like it's new Mac time. You can use your Time Machine back up from the 2015 to migrate to a new Mac by following the directions below:
When you buy a new Mac the easiest, quickest and most reliable method to migrate from the old Mac to the new Mac is to simply connect the old Mac's Time Machine External Hard Disk to the new Mac using a USB cable before you turn on the new Mac. You will likely need a USB A to USB C adapter, you can find them on Amazon for $10 or less. When you start the new Mac for the first time it will startup Setup Assistant (SA), SA will get to a point where it asks if you are migrating from another computer, select Yes and follow the on-screen prompts and it's done! It is THAT simple.
If you have already done SA on the new computer then simply connect the Time Machine External Hard Disk using a USB cable and launch Migration Assistant (MA) which is located in Applications - Utilities - MA. Then follow the on-screen prompts.
The ONLY difference between MA and SA is MA will create a new user account that you need to log into.
Both SA and MA migrate applications (not 32 bit apps), data files & settings. They do not migrate Mac OS itself. Some professional apps such as Adobe and Microsoft apps may require re-installing their apps as they will not allow them to be migrated. As long as you kept the security keys for installing their apps, it is not an issue.
Finally, never EVER use Wi-Fi when doing Setup Assistant or Migration Assistant. Why, it simply fails in most cases. Please read and follow the directions in Setup Assistant and Migration Assistant. If you do not have a Time Machine backup of the older Mac then create one! If you are not aware of Time Machine, please read Back up your Mac with Time Machine and finally if you need an External Hard Disk to use as a Time Machine External Hard Disk then many experience users on these forums prefer the OWC Mercury Elite Pro due to it's reasonable price, high level of quality and ease of use.
The last thing I can offer before declaring it dead is connecting with a wired keyboard and ensuring it is shut down. Then unplug power from the back of the computer for about 5 minutes. Then plug it back in, then hold down the power button for about 15 seconds.
If it still will not start it sounds like it's new Mac time. You can use your Time Machine back up from the 2015 to migrate to a new Mac by following the directions below:
When you buy a new Mac the easiest, quickest and most reliable method to migrate from the old Mac to the new Mac is to simply connect the old Mac's Time Machine External Hard Disk to the new Mac using a USB cable before you turn on the new Mac. You will likely need a USB A to USB C adapter, you can find them on Amazon for $10 or less. When you start the new Mac for the first time it will startup Setup Assistant (SA), SA will get to a point where it asks if you are migrating from another computer, select Yes and follow the on-screen prompts and it's done! It is THAT simple.
If you have already done SA on the new computer then simply connect the Time Machine External Hard Disk using a USB cable and launch Migration Assistant (MA) which is located in Applications - Utilities - MA. Then follow the on-screen prompts.
The ONLY difference between MA and SA is MA will create a new user account that you need to log into.
Both SA and MA migrate applications (not 32 bit apps), data files & settings. They do not migrate Mac OS itself. Some professional apps such as Adobe and Microsoft apps may require re-installing their apps as they will not allow them to be migrated. As long as you kept the security keys for installing their apps, it is not an issue.
Finally, never EVER use Wi-Fi when doing Setup Assistant or Migration Assistant. Why, it simply fails in most cases. Please read and follow the directions in Setup Assistant and Migration Assistant. If you do not have a Time Machine backup of the older Mac then create one! If you are not aware of Time Machine, please read Back up your Mac with Time Machine and finally if you need an External Hard Disk to use as a Time Machine External Hard Disk then many experience users on these forums prefer the OWC Mercury Elite Pro due to it's reasonable price, high level of quality and ease of use.
So, you don't leave us much wiggle room, but need to ask...
Are you usng a wired USB Keyboard? Wireless is famous for not working when you need it most.
Holding Option key at startup doesn't eventually bring up a Boot Menu?
CMD+r doesn't bring up Restore Mode?
Have you done a PRAM reset, CMD+Option+p+r...
Reset NVRAM on your Mac - Apple Support
In fact, do 3 in a row, takes a bit of time.
Intel-based Macs: Resetting the System Management Controller (SMC)...
Reset the SMC of your Mac - Apple Support
1.. Shut the machine down.
2.. UNPLUG the power lead to the computer and any peripheral devices.
3.. leave it for 10 minutes.
4.. Hold power Button in for 10 seconds
5.. Connect everything back up and restart.
I have a wireless keyboard but after your message I tried all of the above with my wired keyboard. Nothing works. When I hold CMD+r and hold the power button the fan revs up then down within a second and then nothing happens.
I am currently waiting the 10 minutes to try your last suggestion.
Thanks!
I'll also mention that my computer locked up and then rebooted before this issue. It took probably 15 minutes to pass the mac icon screen with the progress bar. It then rebooted and said something about my imac rebooted due to an issue. I can't recall the exact error. I had to hit a key to continue. This is when it eventually went black and to this point.
I took off the screen and the hard drive seems fine. I am copying things off to my mac mini. Any thoughts on what I can test or look for?
Thanks,
27" iMac late 2015 Black screen loud fan
