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MBP 15 on a 777 airliner with AC power - strange behavior

L

likegadgets

macrumors 6502a
Original poster
Jul 22, 2008
790
358
US
I just took a transatlantic flight on a newish 777 that had AC power at the seat.
My MBP 15" unibody behaved strangely. The Magsafe connector turned green as usual, and the MBP indicated: "charging" but the mouse (built in pad) became all jumpy, it was imposible to control, and the connection introduced noise on my headphones. Unplugging the Magsafe from the MBP restored mouse control and stopped sound interferance,

The AC charged my iPhone (smaller AC adapter just fine).

I tried:
1) A second AC plug in another seat - same issue
2) A second AC adapter (I travel with two)

Same issues remained.
Another passenger had a MB Air and had no problem. Other passengers had PCs of various sizes with no problems.

I know the MBP adapter draws more power, but it is a standard AC 110v plug and it seemed to be the only machine with the issue. No one seemed to have another MBP in the cabin so I could ask. I decided not to continue with the AC plugged in - just in case. Upon arrival it has worked just fine in several Hotels.

Anyone experienced this issue on an Airplane?
 
likegadgets said:
I just took a transatlantic flight on a newish 777 that had AC power at the seat.
My MBP 15" unibody behaved strangely. The Magsafe connector turned green as usual, and the MBP indicated: "charging" but the mouse (built in pad) became all jumpy, it was imposible to control, and the connection introduced noise on my headphones. Unplugging the Magsafe from the MBP restored mouse control and stopped sound interferance,

The AC charged my iPhone (smaller AC adapter just fine).

I tried:
1) A second AC plug in another seat - same issue
2) A second AC adapter (I travel with two)

Same issues remained.
Another passenger had a MB Air and had no problem. Other passengers had PCs of various sizes with no problems.

I know the MBP adapter draws more power, but it is a standard AC 110v plug and it seemed to be the only machine with the issue. No one seemed to have another MBP in the cabin so I could ask. I decided not to continue with the AC plugged in - just in case. Upon arrival it has worked just fine in several Hotels.

Anyone experienced this issue on an Airplane?
Click to expand...

Most stock WB aircraft are configured for only 65W power draw from inseat empower and standad power ports. I bet the MBP's strange behavior could have been associated with this power draw issue. I guess you didn't try plugging your MBP into another power port to see if the same thing happened. The Apple magsafe airline adapter, however, should work as normal. I am assuming you probably flew on a 777-300ER/LR/77W since having standard power pronged power ports is still a rarity in the 772 and 773.
 
the other night I went to charge my iphone. While charging the screen became erratic, it would recognize taps or swipes.

Change chargers and work fine.

Does it do it only in the air? or while on the ground in a hotel persay
 
Aboo said:
Most stock WB aircraft are configured for only 65W power draw from inseat empower and standad power ports. I bet the MBP's strange behavior could have been associated with this power draw issue. I guess you didn't try plugging your MBP into another power port to see if the same thing happened. The Apple magsafe airline adapter, however, should work as normal. I am assuming you probably flew on a 777-300ER/LR/77W since having standard power pronged power ports is still a rarity in the 772 and 773.
Click to expand...

It is a 777-200; every First and Business seat had a 110v AC adapter. I actually did try this on 3 different seats - same behavior.
 
bruinsrme said:
the other night I went to charge my iphone. While charging the screen became erratic, it would recognize taps or swipes.

Change chargers and work fine.

Does it do it only in the air? or while on the ground in a hotel persay
Click to expand...

As I mentioned, I travel with two AC adapters - I tried both. No problem either at home 110v or in two hotels upon arrival that are 220v - with either of my adapters,
 
likegadgets said:
It is a 777-200; every First and Business seat had a 110v AC adapter. I actually did try this on 3 different seats - same behavior.
Click to expand...

Aah didnt know you flew J/F. I though you were in Y, hence my initial comment. Regardless, I have feeling that you were expierencing a power draw issue. Do you the Apple Airline adapter by any chance?
 
Aboo said:
Aah didnt know you flew J/F. I though you were in Y, hence my initial comment. Regardless, I have feeling that you were expierencing a power draw issue. Do you the Apple Airline adapter by any chance?
Click to expand...

The plane only had the 110v standard AC adapter - no longer the other 12v type, so I did not take any adapter other than the 85W standard MBP adapter
 
There was probably just a lot of noise in the power. You said you heard noise in the headphones. The noise would travel through the magsafe adapter if it has inadequate filtering (it probably has just enough filtering for "normal" use), then would cause all kinds of problems in the laptop's circuitry. The problem could be easily diagnosed with an oscilloscope, but good luck getting that past security!

Was the connection grounded? Did you use the grounded (3-prong) cord? It would be interesting see if grounding has any effect on the problem if it is available on the plane.
 
m85476585 said:
There was probably just a lot of noise in the power. You said you heard noise in the headphones. The noise would travel through the magsafe adapter if it has inadequate filtering (it probably has just enough filtering for "normal" use), then would cause all kinds of problems in the laptop's circuitry. The problem could be easily diagnosed with an oscilloscope, but good luck getting that past security!

Was the connection grounded? Did you use the grounded (3-prong) cord? It would be interesting see if grounding has any effect on the problem if it is available on the plane.
Click to expand...


The plug was 3 prong. My magsafe is the standard two prong. I have no idea if the jet had grounding.
 
likegadgets said:
The plug was 3 prong. My magsafe is the standard two prong. I have no idea if the jet had grounding.
Click to expand...

If it was a grounding issue, I would also expect some static discharge from the body of the MBP itself. Did you experience any of this? The feedback/noise in the headphones though does sound like a grounding issue.
 
This has been a problem ever since the first Intel MBP was launched. The power adapter on a MBP is 85 wats and the most power at the seat is 75 wats.

On 777, 767, and 757 that have power plugs in first/business I have found the green light goes to red when I plug my MBP in and I get no power.

On Qantas 747's I actually "trip" the ciricut breaker on the plane and can't use it either. My friend had an old power book and it worked just fine, as I think it has a 65 wat power supply.

Does anyone know a work around for all of this? The last time I asked the best responce was "if you can afford to fly international business or first, you can afford to take along a MBA just for your flights".... not really the solution that I wanted to hear.

I know there is an EM power adaper for the MBP but most planes now have normal 110 outlets at the seats.
 
Lets all face it. even though 75w may be the MOST power a seat on a plane will put out, he probably didnt require that much? My point is even though the MBP requires 85w, it doesnt always use that. When Idle probably about 50% of that. Even when charging, if he wasnt gaming, we are maybe talking what 65-70w usage?

Just my two cents. The static headphones lead me to believe it was an interference issue...???

EDIT: Ihave used a MB brick (65w) on my uni-MBP while chargin and on 9400. It behaved just fine, and charged normally. If power was in fact the case, surely My mouse wouldve been the same as his, no?
 
Question-

Will a normal 60 wat MacBook power supply work with a MBP? If so, there is your answer. I don't have a MacBook, so I can't see if the Magsafe adapter is the same size and what will happen when you plug it into a MBP and try to run it.
 
I, too, am having difficulty understanding this as just a power draw and power draw issue only. Unless you are charging the battery plus using a lot of power intensive applications, you shouldn't be drawing the full 85W from your adapter.

I'd be interested to know what the exact conditions and procedure the TS used. IE, in what order were objects plugged in and what was the state of the battery.
 
TXCraig said:
Question-

Will a normal 60 wat MacBook power supply work with a MBP? If so, there is your answer. I don't have a MacBook, so I can't see if the Magsafe adapter is the same size and what will happen when you plug it into a MBP and try to run it.
Click to expand...

This is very possible. I have in the past, by accident, been running on a classmates 65 watt macbook power supply. Both worked just fine the entire time.
 
TXCraig said:
Question-

Will a normal 60 wat MacBook power supply work with a MBP? If so, there is your answer. I don't have a MacBook, so I can't see if the Magsafe adapter is the same size and what will happen when you plug it into a MBP and try to run it.
Click to expand...


I believe it will. The MBP will see it's a 60 watt adapter and adjust accordingly. The battery may take longer to fully charge, but it should work.

In your case, the MBP saw an 85 watt adapter and was expecting the full 85 watts, and when it wasn't getting it, it went nuts. At least that's my guess...
 
yg17 said:
I believe it will. The MBP will see it's a 60 watt adapter and adjust accordingly. The battery may take longer to fully charge, but it should work.

In your case, the MBP saw an 85 watt adapter and was expecting the full 85 watts, and when it wasn't getting it, it went nuts. At least that's my guess...
Click to expand...


I cant imagine he had the CPU pegged, GPU pegged, battery charging, and everything turned on though from what he said you know???

Something seems off here. I still think interference of some sort. Then again electricity is a you know what :)
 
On my return flight I used the long cable with grounding and it worked fine. 85W and all.
 
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