my macbook pro does not detect external display anymore

I becoming more and more frustrated with these issues. I propose everybody to use this blog and inform your community through twitter about this problem that Apple has to fix.

I'm realy considering to quit with apple computers.

you can see my twitter anouncement on @janwillemtromp

Hi Apple you are disapoitting me a lot with this issue. I mean a lot.

You look like a chinese prankster brand with stuff like this.

I bought a Macbook Pro, and already spent an afternoon with this lame issue. When i bought i was hoping to see something PRO but all i see its my monitor dark not detected. The only time it was detected, for the first time i connected it was working with a little delay. So not good too.

Let me tell you guys that 17 pages of ppl begging for help it is not an issue for you, i dont know how is your level of care for the customer. Suppose the same that an white brand customer.

Something like sorry we are working to solve this would be enough for me. I am patient.

But don t like to be cheated.

To be honest i just bought this apple product. And thats just cause i love logic pro studio.

And even that... someone told me that you will stop updating.

So... good requiem for you guys.

You apple is not good this year. I had mine covered with vinyl.

Cheers and if you feel in need to be a good brand you can send me asap an working solution for this drama issue to my email since i will not return here hoping to see an answer cause 17 pages of asking help were not legit for you guys.

King regards.

Miguel Bernardo

What cable will connect my MacBook Pro running 10.8 to an InFocus Projector (IN 21002 EP)?

I am having this same issue I've seen so many people about on the Apple Support boards, the only difference being that I know EXACTLY what caused it, just don't know how to fix it. I have a new Macbook Pro with 2 different APPLE Brand Mini dv HDMI connectors & 3 different brands of HDMI cords. All of these in combinations have ALWAYS worked to connect my Macbook Pro to any of my 3 TVs. A couple of nights ago, however, I was successfully watching a movie on my SONY HDTV but having connection problems. I opened up Activity Monitor and "Force Quit" a few processes taking up a lot of space. NOW, AFTER doing that, neither of my TVs here are being detected as a display. The Macbook screen goes blue for a second or two upon connecting (like it always does) but the TV still says no signal after. Because of all of this, I'm 99.999% positive the issue that I'm having (& probably A LOT of you all on here) is some kind of display process accidentally being quit. Can someone please tell me how to fix this?

WOW!!! Oddly enough, as soon as I posted this, for the first time in 3 days since my issue occured, it just worked! THE ONLY THING I DID: opened Activity Monitor back up...searched "all processes" & "inactive processes" for DISP...."prl_disp_service" popped up...I clicked view sample, had to enter my root password, was given a text-edit "sample log" code, exited out....BOOM works again on all 3 TVs. Don't know if those steps have anything to do with or if it was just dumb luck. But after contacting Apple & trying EVERYTHING for days, that's what finally got it working again, NO RESTART, SOFTWARE UPDATE, RESTORE, NO UNPLUGGING ANY CABLES, NOTHING except doing those steps, then hitting input through all of the options back to the HDMI2 option I was initially on & it's working. Hope that can help is some way.

i dont even see "prl_disp_service" come up anywhere... that all seemed a little too good to be true

I googled it, it's a Parallels Desktop application, which I don't even have Parallels on here, but there were a couple of other Inactive Processes I screwed around with that looked like they might have something to do with "DISPLAY" "MONITOR" "EXTERNAL" I have no clue exactly what it is but I'm conviced it has something to do with Activity Monitor & processes on there because the first time mine stopped working in yrs of watching movies on externals practically every day, is right after I did a "Mass-Force-Quit" to a bunch of processes after getting ****** about my connection. What happened right after that sounds exactly like all of the other issues I've read on here.

I'm sorry you're still having problems--but your old fix works for me really well! In case no one wants to scroll up to the original:

1)unplug connection cords from mac

2)Unplug power from external monitor

3)plug in monitor connection cords to mac

4)plug monitor into outlet and turn on

it stopped my blue screen flicker! Full disclosure: I haven't done the latest firmware update yet, and now I'm a little afraid to.

I have plugged, unplugged, powered off, powered on in every possible combinations between my MBP and Sony Bravia.

Refusing to buy any Apple product that will "cure" the issue, which I do think it has something to do with Mountain Lion, as both my MBP and Air used to be able to seemlessly detect the HDMI cable and I was able to mirror my computer display onto my TV monitor, I now have Hulu+ added to my Wii....

Still very disappointed in the Apple developers that they can't come up with a ML update so that it detects displays as Snow Leopard did.....

Anyone know if the new update 10.8.3 fixes this issue for ML?

I hope it does, if so, I will post it and be very happy. I will check for the update as I have 10.8.2

Hi everyone. Seems I've befallen this same cursed problem as well. I am using a 3 month old out of the box, MBP and had it working fine connecting to my Samsung 24" display (via an old VGA connector mind you) and then today - bam. No reason but it refuses to work. Even worse my MPB screen goes completely grey when I try to connect.

I updated to 10.8.3 last night - not sure if this update had anything to do with it but judging by previous posts it seems this is a much older issue.

Apple's lack of action in dealing with this is very poor indeed.

The update of ML did not solve the issue of the HDMI connection. When I connect the hdmi adaptor into the MBP, the screen still flickers and my Sony Bravia cannot get the signal.

The one thing that was different was that prior to connecting to my TV, I was at least able to get the message in my system preferences that the MBP was able to detect a display...then once connected to the tv, the MBP screen flickers and as I said, not signal detected.

After posting here the other night, messing with activity monitor, and getting my external display to finally work again, it's gone out and keeps saying "no signal" again. I've tried 3 different cords, 2 different adapters, & 2 HDTVs again..also all of the unplugging, replugging tips listed...NOTHING. This all started about a week ago for the first time after never having had 1 problem with external displays for years. I didn't install anything new, didn't update anything, didn't do anything but force quit a lot of things on Activity Monitor that were using a lot of CPU. ANY OTHER SOLUTIONS TO TRY???

Some success this morning. Replaced the VGA to DVI cable and simply used a DVI/HDMI cable and it worked on my Samsung 24" Display. But now when trying to connect to my Apple 24" Display it doesn't work.