Error #6085 halfway solved! (MBox-Pro3)

[rickymix]

I've been trying to get my new MBox-Pro3 / PT10.3.3 / MacBook-Pro / OSX 10.8.2 system running but kept getting the 6085 error. Reading the posts here it seems a lot of others have had this problem without anybody solving it. While emailing AVID support I sorted out some of my problems and figured I should post them here, FYI. Will post AVID's response to the rest when they reply.
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"Hi. I got my new PT 10.3.3 software and MBox-Pro 1.1.3 drivers installed in my new MacBook Pro 2.9 GHz i7 laptop, but unfortunately I can't playback a simple session for more than 20 or 30 seconds without it crashing with Error 6085. I've gone through all the DUC recommended optimizing, preference, database procedures, turned off WiFi, Bluetooth, Screensaver, etc, and of course all the possible "Playback Engine" possibilities, but still get the 6085 error.

The problem ONLY occurs when I use 2 Firewire devices at the same time; the MBox-Pro and my external G-Drive hard-drive (FW800). Separately they work fine, if I:
a.) use the MBox-Pro while running an session completely from my MacBook's internal hard drive. Or
b.) if I run a session from the external G-Drive but without the MBox-Pro, using my computer's "Built In Outputs".

Separately they run rock-solid, so obviously there's a FireWire buss conflict. My MacBook only has 1 FireWire output, so I'm daisy-chaining from MacBook > G-Drive > MBox-Pro. When I try it the other way, with the external G-Drive hard-drive plugged into the back of the MBox, the G-Drive doesn't even function; the lights don't come on, the computer doesn't see it, and I've tried both the FW ports in the back of the MBox. I tried a different FW external drive in back of the MBox and it doesn't work either.

... Oh, wait! As I've been typing I tried the other external drive (FireLite FW400) in the first position, (MacBook > FireLite > MBox) and it's been running flawlessly for 20 minutes!!!! They're both "Mac OS Extended Journaled" formatted, 5600 RPM.

... OK, so I've now also tried 2 other FW400 drives, (all 3 daisy-chained before the MBox at the same time), and they're all rock solid! That's a relief, but I wonder if my main FW800 G-Drive is flawed somehow, or is there perhaps a FW400 vs FW800 issue?

... OK, so now I tried the 3 FW400 drives all daisy-chained AFTER the MBox, (MacBook > MBox > FW400 > FW400 > FW400). The 2 FW400 drives which were powered by wall-warts worked fine, rock-solid, but the one requiring FW powering did not show up/light up/function at all.

So I've solved some of my own problems here, thanks for bearing with me. My remaining questions are:
1.) Should a FW800 external hard-drive work with the MBox-Pro 3?
2.) Would a Thunderbolt or USB-3 external hard drive be better? (7600 RPM).
3.) Should a FW-buss-powered external drive work when daisy-chained AFTER the MBox-Pro 3, or is my MBox defective because it's not passing FW-buss power?

Thanks for your help, patience and expertise!
Rick.

technical details:
Mbox Pro (3rd Gen)
Protools 10.3.3
MacBook Pro 2.9GHz Core i7 13
8 GB RAM
Apple Mac OS X 10.8.2 (Mountain Lion)"

[rickymix]

Got a surprisingly quick response back from AVID support, confirming what I had suspected: FireWire-800 drives DO NOT work with the MBox Pro, or the other Gen-3 MBoxes, although for years mine worked great with my original MBox, (Gen-1).
Also, the FW ports on the back of the MBox DO NOT provide power to FW buss-powered hard-drives. Any external hard-drive you plug in there will need to be plugged into wall power or it won't work at all.
Also, AVID recommends 7600 RPM drives, although my old 5600 RPM FW-400 drives seem to be working just fine for me so far. I'm buying a new Thunderbolt drive myself.
Hope this info helps others. I just wish it had been more clearly presented by AVID in the first place. Below is AVID's response to my questions, also with a FAQ which others might find useful:
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Thank you for contacting Avid Audio Support.

Regarding question

1.The Mbox has a firewire 400, so the firewire 800 is not supported with it.

2. Yes a Thunderbolt or a USB-3 would be better for your external hard drive.

3. The Mbox Pro give no power out in a daisy-chain. So I think because of that the FW-buss-powered external drive is not working.

Regarding the error 6085 try the following FAQ:
http://avid.force.com/pkb/articles/e...ssage/en418191

[serio]

When they say firewire 800 is not supported they mean that your entire daisy chain (if you're running one) should be running at 400. ALL Mboxes work fine with 800 drives as long as they are NOT in the same chain as the interface. Some firewire 800 drives can be ran at 400 speeds (they have FW400 connectors) and will work in a chain with the mbox as well though.
Glad you're getting rid of the problem and glad you posted this as I speculate many many problems with firewire interfaces and pro tools can be resolved by following the advice to keep the device chain at 400 speeds or running a different type of connection for your HDD.

[rickymix]

Hi Serio, you're right, that's exactly what I'm discovering. My MacBook laptop only has 1 FW(800) port, forcing me to daisy-chain.
So I went to Apple and bought a Thunderbolt-to-FW800 connector, and set up my rig with the FW800 (5400-RPM) external G-drive connected through the laptop's Thunderbolt port and the MBox-Pro3 connected through the laptop's FW800 port via a FW800 > FW400 adapter.
My ProTools is running rock-solid now! If I run into problems in the future due to heavier track counts/VI's/Plugs etc, I'll upgrade to a 7200-RPM external hard-drive, but for now I'm up and running without a glitch.
I only wish that AVID would make this info much more obvious in the basic FAQs on the MBox-3 line; particularly that the MBox-3s are FW400 ONLY and will NOT run properly on the same FW buss as a FW800 device. Also that there is no FW-buss power coming out of the FW400 ports on the back of the MBox units. Hard-drives daisy-chained there MUST have their own DC power supply.