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secondary monitor

Help! I have a 2013 iMac running on Catalina. I have tried to set up a second monitor, with no luck. Tried a new GTEK external monitor utilizing all sorts of different ports/connections. And, tried to use my old 2010 MacBook Pro. Nothing. But, the GTEK monitor worked fine with my husband's 2017 iMac. I don't get it. Ideas? Thanks so much!

iMac Pro

Posted on Feb 23, 2022 5:56 PM

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Posted on Feb 25, 2022 10:06 AM

It may be as simple an issue as your old display in not compatible. I would also try doing two things.


On the 2013, please create a new account and call it TEST ACCOUNT, log into the account and see if the external display works. If it does that indicates a software issue on your normal account that needs troubleshooting.


The second option is to test another external display and see if that works okay, if it does then you know the problem is with your old display.

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Question marked as Top-ranking reply

Feb 25, 2022 10:06 AM in response to oohlolaw

It may be as simple an issue as your old display in not compatible. I would also try doing two things.


On the 2013, please create a new account and call it TEST ACCOUNT, log into the account and see if the external display works. If it does that indicates a software issue on your normal account that needs troubleshooting.


The second option is to test another external display and see if that works okay, if it does then you know the problem is with your old display.

Feb 23, 2022 6:15 PM in response to oohlolaw

Howdy , oohlolaw… you could try the following:

1-reset smc/pmu*

2- zap pram 4x on startup… restart your iMac, hold down Apple+option+p+r together for 4 chimes/bongs, then let go of all keys and let imac startup as per usual.

3- if you hold down the ‘D’ key on startup that’ll get you apple diagnostics

4- start up in safe mode ( hold down ‘shift’ key on startup until you see ‘safe mode’ on screen) … it’s slower to startup than usual startup so you have to be patient


that’s all i got


John B


* here’s how to do that ( see link) https://www.macworld.com/article/224955/how-to-reset-a-macs-nvram-pram-and-smc.html


secondary monitor

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