DJM 900 stops being recognized as output device.

I'm not sure -- I've opened a ticket with the engineers, they may have some questions for you to provide more detail.

Thanks, Pulse! Hope to hear back soon.

Okay, the engineers have asked...

1. Model number of his MacBook Pro. 
   
2. Are SSD and HDD internal or external, respectively? 
   
3. Where is the OS located, on SSD or HDD? 
   
4. Version of the firmware and driver of 900NXS. (Just to make sure although he stated that they are the latest version.) 
   
5. DJ application’s name he uses. 
   
6. Settings of the DJ application and the driver? 
   
7. Does the problem always happen after the computer wakes up from sleep-mode? 
   　If it is not so, how many % does he experience the problem after his MBP being idle? 
   
8. Does the problem occur also when he manually selects “Sleep” form the menu of Apple and then wakes it up?

1. MD3133xx/A

2. Both external

3. SSD

4. firmware: 1.21 driver: 1.30

5. Serato, but I unplug the 900 when I use my SL1. I only use the 900 as an audio output for OS X.

6. I don't think this is relevant. See above.

7. Not always, but I'd say about 30-40% of the time.

8. I just tried about 4 times, and they all worked fine.

for #2. I meant INTERNAL. Sorry about that.

Engineers have asked...

1. MD3133xx/A is supposed to be the model of Late 2011 with CPU 2.4GHz, but we noticed that you mentioned “MacBook Pro early 2011 (i5 2.3ghz, 4gb ram, 120gb SSD boot drive, 750gb HDD) OS X 10.6.8.” in the first post. Which is correct?

2. You said both SSD and HDD are internal. Is this correct? If so, this is not a standard model. How did you modify it? Yourself, at an Apple Store or at other shop? 

3. What is the maker and model of SSD.

4. You said that you do not use DJM900 and SL1 at the same time. Is this correct? 

5. If you only use the 900 as an audio output for OS X, does it mean that you do not use any DJ application on the Mac when you use DJM-900? 

1. You are correct. I googled the number and I mistakenly looked at the late '11 model number. I just looked on the box and the model number for mine is MC700LL/A. I apologize about that!

1. This is not a standard configuration. I replaced the optical disk drive with an SSD. Just to be clear, I'm using a regular Western Digital 750gb HDD in the regular drive bay, and an OWC 120gb SSD in place of the optical disk drive.

3. 120GB OWC Mercury Extreme Pro SSD (uses Sandforce controller)

1. Correct. Only one or the other stays plugged in. Never at the same time.

2. This is correct as well. I do not use the 900 for anything DJ-software related. I do, however, use it as an audio output for OS X and DAWs such as Reason 6.

Thanks - I've passed that info to the engineers.

Just wanted to update this thread. :)

I upgraded to the newest firmware, and I'm still experiencing the same issues.

The engineers have tested the situation with the same model MBP (but obviously without the modification) and after sufficient testing time were unable to replicate the errors as noted.  As they have not received similar complaints from other users, they assume that this case is a user-specific problem generated under your unique environment, therefore, they regret that they will not be able to provide any further support on this issue.

Fair enough. Thanks for the help anyway. :)