Sidebar Sidebar
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

Macbook Pro Thunderport stops working with external display after power adaptor goes on and off :(

J

joyagirl

macrumors newbie
Original poster
May 25, 2012
23
0
Hello,

My Macbook Pro has been working perfectly with my Samsung 27" external display, until my power adaptor clicked on and off repeatedly due to a dodgy power splitter. The screen flicked on and off as the Macbook switched from mains powered to battery powered repeatedly for about 5 seconds.

Now the Macbook detects the Samsung display, but nothing shows up on the Samsung. When I use a different Macbook the Samsung still works perfectly (with the same thunderbolt to HDMI cable), so I think the problem is the Macbook. The Macbook still pauses and flashed the blue screen when the cable is plugged in, and it detects the Samsung. Is it possible that the Macbook is stuck on some mode due to the power adaptor flicking on and off before? Or is it possible that the thunderbolt port is broken, but it still detects the Samsung and the Macbook still recognises when something is plugged into the thunderbolt port?

Thanks in advance!

x
 
Try to reset your power adapter. Unplug, and make sure the adapter is not plugged in to power. Let it sit for about 10 minutes, unconnected.
Leave your external display disconnected from your MBPro.
After the 10 minutes, try an SMC reset: Turn off your MBPro.
Plug in the power adapter. You should see the LED on the plug.
Press and hold Shift-Control-Option, then, while holding those 3 keys, press and release the power button.
Release all the keys. If the LED on the power adapter is orange, it should change briefly to green, then back to orange. If the LED is already green, then you won't see any change at all.
I will always do a PRAM reset at this point. It's not really necessary, but makes me feel better :D
So, Press and release the power button, then immediately press and hold Option-Command-P-R
You should hear the boot chime sound. Keep holding those 4 keys until you hear the boot chime 2 more times.
Release the keys, and let your MBPro boot up normally.
Once you get booted up, be sure to set the Startup Drive in your System Preferences (that will be unset by the reset)

Shut your MBPro off.
Connect your external display, and power it on.
Turn on your MBPro again.
 
  • Like
Reactions: joyagirl
Hi DeltaMac,

Thanks for you advice!

I followed it step by step, did the SMC and PRAM resets. The orange light of the adaptor turned from orange to green, then back to orange. With the PRAM reset I even heard the boot chime three times. But nothing seems to have changed sadly...

Any other ideas? My friend's Macbook Pro works perfectly with the Samsung, but my one doesn't. Like I said, it worked perfectly up til last night when the power adaptor went on and off repeatedly, making the external monitor switch on and off in quick succession. I downloaded and tried something called gfxcardstatus, but it didn't fix the problem.

Is it possible that there's a hardware fault, even though the Macbook Pro still seems to recognise it when the HDMI cable is plugged into the thnderbolt port?

ps: This is a 2011 Macbook Pro 15", running Snow Leopard 10.6.8.



DeltaMac said:
Try to reset your power adapter. Unplug, and make sure the adapter is not plugged in to power. Let it sit for about 10 minutes, unconnected.
Leave your external display disconnected from your MBPro.
After the 10 minutes, try an SMC reset: Turn off your MBPro.
Plug in the power adapter. You should see the LED on the plug.
Press and hold Shift-Control-Option, then, while holding those 3 keys, press and release the power button.
Release all the keys. If the LED on the power adapter is orange, it should change briefly to green, then back to orange. If the LED is already green, then you won't see any change at all.
I will always do a PRAM reset at this point. It's not really necessary, but makes me feel better :D
So, Press and release the power button, then immediately press and hold Option-Command-P-R
You should hear the boot chime sound. Keep holding those 4 keys until you hear the boot chime 2 more times.
Release the keys, and let your MBPro boot up normally.
Once you get booted up, be sure to set the Startup Drive in your System Preferences (that will be unset by the reset)

Shut your MBPro off.
Connect your external display, and power it on.
Turn on your MBPro again.
Click to expand...
 
While I can offer no help as to your issue, apart from having you try with another monitor to rule out the MacBook Pro itself, I strongly urge you upgrade to the latest version of OS X for compatibility and security reasons, unless you use software which will not run on a newer OS X.
 
I use a lot of old software so I switched back from Lion to Snow Leopard (also Snow Leopard felt faster to me). But if upgrading can fix the external display issue then I'd consider upgrading.

Is there any chance this is not a software problem but is a hardware problem (i.e Thunderbolt connection still recognises cable even though it's broken)? I don't have another display to test unfortunately, only another Macbook Pro.

snaky69 said:
While I can offer no help as to your issue, apart from having you try with another monitor to rule out the MacBook Pro itself, I strongly urge you upgrade to the latest version of OS X for compatibility and security reasons, unless you use software which will not run on a newer OS X.
Click to expand...
 
If the display, with your cable, works on a different MBPro - then you should try a different cable.
That will be a lot simpler than finding a different display to try.
(It's possible that there is some problem with the cable now, which may work connected to a different computer, but is marginal. )
Anyway, if your display does not work with a different cable, but still works on your other MBPro, then I will expect that your port has failed. That will need a replacement logic board.
But, if the connection recognizes "something" plugged in, then (again) a different cable will help decide if the port is the problem, or you just need a different cable.

You didn't say which MBPro you have? Does yours have an HDMI port? That would at least give you another option to try...

And, it may be worth your time to take to a "Genius", or to an Apple-authorized service shop, where they could test several different options. Gets expensive to think about replacing the logic board (or giving up and replacing with a new MBPro), and you may be missing something simple, like a good cable.
 
Hi, I've tried using a thunderbolt to DVI adaptor and then a DVI cable with my MBP and it still doesn't work with the Samsung display. Though again the Macbook Pro seems to recognise the Samsung when the cable is plugged in, but the Samsung display is not getting any picture.

The Samsung goes into or stays in sleep mode (power LED blinks, blank screen) when my 2011 MBP is plugged in, but when my friend's 2012 MBP (Mountain Lion) is plugged in the Samsung immediately wakes up and works.

I really hope the thunderbolt port is not broken as my Applecare ran out earlier this year and I never got to use it as the Macbook has never had any issues. This is a 2011 model and there's no HDMI port, only thunderbolt. It'd be disappointing if the thunderbolt would die just because the power adaptor flicked on and off a few times. But still if the thunderbolt connection is fried then shouldn't it just not work at all? The Macbook still freezes and flashes the blue screen like it should whenever the thunderbolt to HDMI cable is plugged in, and the Samsung then shows up under "Display" in System Preferences...

Thanks for all your help so far.



DeltaMac said:
If the display, with your cable, works on a different MBPro - then you should try a different cable.
That will be a lot simpler than finding a different display to try.
(It's possible that there is some problem with the cable now, which may work connected to a different computer, but is marginal. )
Anyway, if your display does not work with a different cable, but still works on your other MBPro, then I will expect that your port has failed. That will need a replacement logic board.
But, if the connection recognizes "something" plugged in, then (again) a different cable will help decide if the port is the problem, or you just need a different cable.

You didn't say which MBPro you have? Does yours have an HDMI port? That would at least give you another option to try...

And, it may be worth your time to take to a "Genius", or to an Apple-authorized service shop, where they could test several different options. Gets expensive to think about replacing the logic board (or giving up and replacing with a new MBPro), and you may be missing something simple, like a good cable.
Click to expand...
 
Yes, I think that you have part of the connection working (senses that a video cable is plugged in, and starts the video (switchover) ). The video device is sensed, then the last thing that happens is enabling the video out. That last part apparently is not happening. I suggest that you take to an Apple Store, where you can hook up to an Apple Thunderbolt Display. If that does not work, you're pretty much done.
 
If the thunderbolt port can indeed be partially broken so that it can sense things but can't send video out, then how much would we be looking at for repair? Such a shame if it does break so easily, there's no other way of connecting to an external display...

I really hoped it's a software issue and the macbook is just stuck on some setting due to power flicking on/off :(
 
joyagirl said:
If the thunderbolt port can indeed be partially broken so that it can sense things but can't send video out, then how much would we be looking at for repair? Such a shame if it does break so easily, there's no other way of connecting to an external display...

I really hoped it's a software issue and the macbook is just stuck on some setting due to power flicking on/off :(
Click to expand...
Everything is soldered onto the board, just like on every laptop on the market. You're looking at logicboard replacement, which can cost upwards of $800.

If you're lucky, you might get the flat repair rate Apple sometimes offers where they fix anything and everything they find broken for about $300. That's at the genius' discretion though.
 
  • Like
Reactions: joyagirl
Take into an Apple store. The "genius" will have a thunderbolt display to try out. You may be surprised that it works (or not :( ) on a different connection, and all you really need is a good cable.
(might happen!)
I guess you were using in clamshell mode (lid closed, with the external display as primary), which would explain all the switching when the power adapter lost power a few times. So, (probably) the internal DP feed to the thunderbolt port is gone.
(As snaky69 suggested!) If you take it to a "genius", be sure to ask about the "flat-rate repair". It's really a good deal... The store ships it to a central repair facility. They will often fix other parts that may not be related to your problem, but will make your experience better, like swapping out a marginal battery, replacing case parts, hinges, etc. Those don't happen on every repair, but you may be pleasantly surprised with what you get back.
 
OP:

You said a 2011 MacBook Pro.

Have you experienced any of the problems associated with "RadeonGate" that these models are prone to suffer from?
 
  • Like
Reactions: joyagirl
Yes my Macbook has AMD Radeon HD 6490M.

I'll give Apple a call. Do you guys recommend taking the Macbook in or sending it to Apple? Just wondering which would have a better chance of them fixing my computer for free - or cheap :) - as I'm really not sure if the current issue is related to Radeongate or not. It'd be great if they could replace my battery too as it's almost dead...

On another note, would a 2013 Macbook Air i7 1.8ghz 256gb outperfrom my 2011 i7 2.0ghz Macbook Pro with Crucial 512gb SSD (for video and audio work)? I might be able to have a Macbook Air if my Macbook Pro is too expensive to repair.
 
Last edited:
Call AppleCare. They will either send you a shipping box, or will suggest that you take to an Apple retail store, or authorized service shop.
 
joyagirl said:
Yes my Macbook has AMD Radeon HD 6490M.

I'll give Apple a call. Do you guys recommend taking the Macbook in or sending it to Apple? Just wondering which would have a better chance of them fixing my computer for free - or cheap :) - as I'm really not sure if the current issue is related to Radeongate or not. It'd be great if they could replace my battery too as it's almost dead...

On another note, would a 2013 Macbook Air i7 1.8ghz 256gb outperfrom my 2011 i7 2.0ghz Macbook Pro with Crucial 512gb SSD (for video and audio work)? I might be able to have a Macbook Air if my Macbook Pro is too expensive to repair.
Click to expand...


You're comparing a dual to a quad core. The 15" still runs circles around the younger MBA.
 
You must log in or register to reply here.
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.
Top Bottom
Back