My late 2014 mac mini was running two monitors but now only one or the other will work

Question

Level 1

9 points

My late 2014 mac mini was running two monitors but now only one or the other will work

I have a late 2014 mac mini 2.6 GHz core i5 with Intel Iris 1536 MB graphics. Until this week I've been running two monitors ... Monitor 1 is an Apple Cinema Display connected via a mini display port to DVI adaptor. Monitor 2 is a HP Pavilion 22xi connected HDMI to HDMI, or sometimes via a mini display port to HDMI adaptor.

For the past year or so (possibly since installing El Capitan but I'm not 100% sure) I've been having intermittent problems where, on restart the mac would only recognise one monitor. I could usually get it to recognise the other by restarting and swapping cables/ports etc. But now all my workarounds have failed and I'm stuck with just one monitor ... my workflow (book publishing design/production) requires a two monitor set-up. Both will work independently but I can get them to work together whatever port, cable or adaptor I use.

I've seen other threads relating to this but never a solution.

Any ideas or suggestions would be gratefully received.

Thanks

John

Mac mini, OS X El Capitan (10.11.4)

Posted on Apr 27, 2016 1:03 AM

Reply

Answer 1

johnddesign Author

Level 1

9 points

Apr 27, 2016 1:25 AM in response to johnddesign

What I meant to say, in the second paragraph, is that ... both will work independently but I CAN'T get them to work together ...

UPDATE: After three days of frustration I have, just after posting my query, managed to get both working ... one via mini display port to DVI and the other HDMI to HDMI. I know it's only a temporary result and I'm considering not shutting down the mac at the end of the day ... still looking for a proper fix!

Reply

Answer 2

lllaass

Level 10

210,411 points

Apr 27, 2016 1:33 AM in response to johnddesign

- Try resetting the SMC and NVRAM/PRAM

Intel-based Macs: Resetting the System Management Controller (SMC)

About NVRAM and PRAM

Also, yo may have a bad adopter or cable.

Reply

Answer 3

johnddesign Author

Level 1

9 points

Apr 27, 2016 1:49 AM in response to lllaass

Thanks for the reply Illaass. I have reset the NVRAM in the past in relation to this problem (though not recently) but never the SMC. Right now I want to keep both monitors on so that I can get on with my work so I'm reluctant to disturb things! But I will try this again and the SMC next time I shut down.

I feel it's unlikely to be a cable issue as all cables work fine independently of each other. But I could be wrong I guess. I'll look at that too if the problem continues.

Thanks

Reply

Answer 4

den.thed

Level 9

77,134 points

Apr 27, 2016 3:18 AM in response to johnddesign

Looks like the HP also supports DVI.

Have you tried running both monitors on Mini Display Port to DVI adapters from the Mini's Thunderbolt ports?

Or one monitor from a Thunderbolt port and the other from the HDMI port using an HDMI to DVI adapter?

Reply

Answer 5

johnddesign Author

Level 1

9 points

Apr 27, 2016 3:36 AM in response to den.thed

Haven't tried this ... Do you think it would make a difference where the thunderbolt port is connecting to? It seems to me to be more an issue of the mac not recognising when two of its outputs are being used. Using the mini-display to HDMI adapter doesn't work any more reliably than HDMI to HDMI .... both can fail to work ... and do. I feel it's a system (software) issue rather than a hardware one.

But thanks ... I'll get another adapter and see if it makes a difference.

Reply

Answer 6

den.thed

Level 9

77,134 points

Apr 27, 2016 5:48 AM in response to johnddesign

I was leaning more towards getting away from using an HDMI cable and using DVI cables out to both monitors.

FWIW I'm running dual DVI monitors in El Capitan and not have any trouble.

Reply

Answer 7

johnddesign Author

Level 1

9 points

Apr 27, 2016 8:05 AM in response to den.thed

Thanks. I've just come back after a couple of hours out ... booted up and zapped the NVRAM as I did so. It's started up fine with both monitors up and running. I've ordered a DVI cable so maybe that will add some stability.

Thanks for your help.

Reply

Answer 8

den.thed

Level 9

77,134 points

Apr 27, 2016 12:10 PM in response to johnddesign

You welcome!

Please come back and share what worked or works, because it always helps others that are having a similar problem.

Reply

Answer 9

johnddesign Author

Level 1

9 points

May 4, 2016 1:31 AM in response to johnddesign

Update: I purchased a Mini display port to DVI adapter, plugged everything in and fired her up and ... everything worked! Great ... that was the end of last week. It worked fine yesterday too but, this morning, I'm back at square 1. Swapped around the leads, zapped the NVRAM, reset the SMC, restarted about a zillion times but only one monitor or the other so I'm stuck now and don't know what to do. I don't have time to mess about with this as I have deadlines looming so I'll just have to get used to working with one monitor while the other stares at me blankly.

Reply