Power cable LED light goes red when CPU is under heavy load.

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Level 1

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Power cable LED light goes red when CPU is under heavy load.

I have started to do a lot of Final Cut Pro 10.1.4 work on my late 2013 15" MacBook Pro Retina. I am using the max CPU at the time which is a quad core i7 2.6GHz. When I am rendering and transcoding video all 8 threads max out and start doing their job, but for some reason when a heavy load like this is happening the LED light on the power cord goes red from green. As soon as the heavy load on the CPU is done the light goes green again. Is the power brick that comes with the 15" MacBook Pro Retina not powerful enough to power the system under full load? That seems wrong. Thanks for any help.

MacBook Pro (Retina, 15-inch, Late 2013), OS X Yosemite (10.10.2)

Posted on Mar 26, 2015 7:24 PM

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Answer 1

spudnuty

Level 5

7,116 points

Mar 26, 2015 8:15 PM in response to jennjun

What wattage is your power adapter? It should be:

"85W MagSafe power adapter with MagSafe 2 style connector"

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Answer 2

OGELTHORPE

Level 9

57,305 points

Mar 27, 2015 4:05 AM in response to jennjun

jennjun wrote:

Is the power brick that comes with the 15" MacBook Pro Retina not powerful enough to power the system under full load? That seems wrong.

There are rare occasions where the power adapter cannot supply enough power for the loads being placed on the MBP. The OSX will then tap the battery for extra power. What you are experiencing is one of those situations which in its own way is 'normal'

Ciao.

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Answer 3

spudnuty

Level 5

7,116 points

Mar 27, 2015 8:19 AM in response to OGELTHORPE

"There are rare occasions where the power adapter cannot supply enough power for the loads being placed on the MBP. The OSX will then tap the battery for extra power. "

That would explain why some machines won't startup with out their battery installed, which is not supposed to happen officially (Service Source) but does.

BTW I looked at the take apart on iFixIt for the external Super Drive and that sure looks like an internal Superdrive just modified for use in that external case. Seen Apple do that before like in the first iMacs where the slot drive was a laptop optical with a different interface card on the back. I'd swap in working iBook drives for non functioning iMac drives.

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