Intermittent Mini Display Port Function

[billywillgo]

Using 09 I-Mac with OS Sierra (10.12.3) connecting to Samsun HDTV


I have my comp hard wired with HDMI cable from Mini Display Port to TV.

For years it worked fine.


Sometime after updating OS is stop recognizing the TV.


Yet sometimes I have been able to get it to work after multiple attempts of shutting down, unplugging, going to "Display", option clicking detect display, opening in safe mode, re opening in normal mode, putting the comp to sleep, unplugging and reattaching cord etc. But I have never been able to figure out what I did that made it work.


At this point I am unable to get it to recognize the TV in the "display" window or in the "sound" window.


So after all this troubleshooting I know it's not the TV, the cable or the MDP to HDMI adaptor I am using. My TV will even change from "no signal" to "no cable connected" if I unplug the HDMI from the MDP adaptor... so I know the connection from my comp is good but yet no signal is coming through.


So obviously the prob is in my computer but again I have no idea why I was able to get it to work the few times it did and I have not been able to repeat the steps I took to make it work.


Help please!!!

Thank you

 

[Cory Cooper]

Hello and welcome.

First two things I would try:
-Reset the System Management Controller (SMC) on your Mac
-How to reset NVRAM on your Mac

Let us know if that corrects the issue.

C

 

[billywillgo]

Hello and welcome.

First two things I would try:
-Reset the System Management Controller (SMC) on your Mac
-How to reset NVRAM on your Mac

Let us know if that corrects the issue.

C

Hello Cory, Thanks for your suggestions but unfortunately after trying both there was no change.
Bill

 

[billywillgo]

And now I ju

Hello and welcome.

First two things I would try:
-Reset the System Management Controller (SMC) on your Mac
-How to reset NVRAM on your Mac

Let us know if that corrects the issue.

C

And now I just went back to my computer (after 15 min) and woke it from sleep mode and it's working. No idea why? I failed to mention that yesterday I basically did the same thing you suggested (rest SMC and NVRAM) only to find it didn't work. But then after a bit more time I came back, woke it, and it worked. So after it started working yesterday I used it a bit, but then when I came back later that night it was not working again. So I'm afraid that even though it's working now it will again for whatever reason stop working. So I'll try letting it sleep, shutting it off etc. and see if it works again or not. I'll be back.

 

[Cory Cooper]

No worries...good luck.

Make sure you are unplugging everything when you do the SMC reset. If it continues and a quick sleep cycle fixes it, then we'll work on that.

C

 

[billywillgo]

No worries...good luck.

Make sure you are unplugging everything when you do the SMC reset. If it continues and a quick sleep cycle fixes it, then we'll work on that.

C

Ok great. Thank you for your response Cory. I'll hope that this time I fixed it... it's still working so far!!
Bill

 

[billywillgo]

No worries...good luck.

Make sure you are unplugging everything when you do the SMC reset. If it continues and a quick sleep cycle fixes it, then we'll work on that.

C

Update. After cruising the web for an hour or so everything was working. I then left the room for about an hour and when I can back and woke the computer it was no longer showing the display icon at the top left of screen so I had again lost the connection. I shut off the computer and did another NVRAM rest and when it came back on there it was! I was again connected. So we've narrowed it down I guess but what does this mean for my computer and how do I address it so it no longer happens? Also I did try putting it to sleep first with no effect. Thanks again for the help.
Bill

 

[Cory Cooper]

Hmmm...

-Which exact model Samsung TV?
-What brand/model is the Mini DisplayPort to HDMI adapter?
-Seems to be happening intermittently when it goes to sleep on its own, correct?
-Have you tried manually putting it to sleep and leaving if for 15-60 mins, then waking it?
-Have you tried  > System Preferences... > Energy Saver > Computer sleep: Never and Display Sleep: 15-60 mins? Also, try unchecking Wake for network access and Start up automatically after a power failure.

C

 

[billywillgo]

Ok. Woke comp this moring and no connection shown. Tried shutting down and on again... no connection shown. Tried to reset NVRAM again... no connection shown. So back to square one I guess, ha ha.
So
#1-I have a Samsung Series 5 LED TV (with updated OS after I tried to solve the problem through Samsung help).
#2-Bluerigger adaptor.
And again it all worked fine for a few years without any connection issues.

Now have I tried manually putting it to sleep and leaving if for 15-60 mins, then waking it? Yes and usually if I have a connection it will be gone, and if I did not I still will not.

I just adjusted the energy saver settings to your suggestions. I'm going to leave now for a bit and Ill put it to sleep and check it upon my return.
Very frustrating have it work and not work, ha ha. Thanks again,
Bill

PS- Just as I was leaving I turned on the TV (no idea if that matters) woke the comp and there it was... I was connected. Shut it off and re-started and there it was... still connected. No idea if changing the energy saver settings as you suggested did it or not? I'll shut it down and be back in a few hours and I'll update!

 

[billywillgo]

Well so far so good. Hopefully your suggestions helped. Thanks again Cory.
Bill

 

[Cory Cooper]

No worries...keep us updated.

C