All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 3 posts ] 
Author Message
 Post subject: Baud rate
PostPosted: September 5th, 2017, 21:19 
Offline

Joined: April 1st, 2016, 21:26
Posts: 59
Location: United States
I have 2 drives from 2 different MacBook Pros.

One is an Apple branded Fujitsu, and the other an Apple branded Toshiba(i can provide model numbers tomorrow if needed).

Both of these drives i have hooked into the UART, and get no terminal output at all. I have tried every reasonable baud rate.

Anything i should know about such drives?


Top
 Profile  
 
 Post subject: Re: Baud rate
PostPosted: September 6th, 2017, 3:02 
Offline
User avatar

Joined: September 8th, 2009, 18:21
Posts: 9746
Location: Australia
Apple used the Tx pin of the UART in some HDD brands/models to report the HDA temperature in real-time. I suspect that the firmware required to support this function would be at ROM level. I say this because one Apple user reports using the PCB of a failed HDD to report temperature information after replacing the HDD with one whose firmware did not support the sensor.

The following post explains the problem:

https://discussions.apple.com/thread/2712496?start=0&tstart=0

Quote:
As mentioned above, installing a replacement hard drive does not allow the HD temperature sensor to work correctly. The original Apple drive has a unique firmware that allows the factory sensor connector to work as the logic board expects. Any drive without Apple firmware will not feed the temperature info to the motherboard and the internal fan speed will eventually crank up to its max RPM. Even installing a new drive that matches the brand of the original factory drive will not stop this from happening. I tried putting a Seagate 7200.xx drive in place of the original 7200.xx drive and the fan still went full tilt boogie.

So, I decided to buy an optical drive sensor (Apple part #922-9141) and use that in place of the original HD sensor. It plugs into the logic board where the old HD sensor did and sticks to the hard drive with an adhesive that is already on the sensor. After installing this and reassembling the computer, the system's fan behavior was normal.


https://www.ifixit.com/Answers/View/85991/replace+the+hard+drive%2C+how+do+I+connect+Hard+Drive+thermal+sensor

Quote:
I overcame the thermal monitoring problem by using the equipment already provided. The hard drive in the mac had failed but the board still had a functional thermistor on it, allowing me to unscrew the PCB from the old hard drive and keep the 4 pin cable attached. Then i tucked this PCB under the new drive and only plugged in the SATA connections into the new drive.

_________________
A backup a day keeps DR away.


Top
 Profile  
 
 Post subject: Re: Baud rate
PostPosted: September 6th, 2017, 4:40 
Offline

Joined: May 21st, 2007, 16:10
Posts: 1436
Location: Gothenburg/ Sweden
fzabkar wrote:
Apple used the Tx pin of the UART in some HDD brands/models to report the HDA temperature in real-time. I suspect that the firmware required to support this function would be at ROM level. I say this because one Apple user reports using the PCB of a failed HDD to report temperature information after replacing the HDD with one whose firmware did not support the sensor.

The following post explains the problem:

https://discussions.apple.com/thread/2712496?start=0&tstart=0

Quote:
As mentioned above, installing a replacement hard drive does not allow the HD temperature sensor to work correctly. The original Apple drive has a unique firmware that allows the factory sensor connector to work as the logic board expects. Any drive without Apple firmware will not feed the temperature info to the motherboard and the internal fan speed will eventually crank up to its max RPM. Even installing a new drive that matches the brand of the original factory drive will not stop this from happening. I tried putting a Seagate 7200.xx drive in place of the original 7200.xx drive and the fan still went full tilt boogie.

So, I decided to buy an optical drive sensor (Apple part #922-9141) and use that in place of the original HD sensor. It plugs into the logic board where the old HD sensor did and sticks to the hard drive with an adhesive that is already on the sensor. After installing this and reassembling the computer, the system's fan behavior was normal.


https://www.ifixit.com/Answers/View/85991/replace+the+hard+drive%2C+how+do+I+connect+Hard+Drive+thermal+sensor

Quote:
I overcame the thermal monitoring problem by using the equipment already provided. The hard drive in the mac had failed but the board still had a functional thermistor on it, allowing me to unscrew the PCB from the old hard drive and keep the 4 pin cable attached. Then i tucked this PCB under the new drive and only plugged in the SATA connections into the new drive.


HDD Temprature report in real time via Tx is only applied to iMac

_________________
Rescue IT Datarecovery service Sweden
Rescue IT Dataräddning Göteborg AB
http://www.rescue-it.se


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 3 posts ] 

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: Bing [Bot] and 29 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group