[DEMUG] all sorts of Firewire issues

[Harry Freeman]

Michele ( + )!( + )

M. Hartman
Power Mac G5 Dual-Core 2.3GHz and 2.5" External FireWire Drive Cases
I've been using external FireWire drives since shortly after Apple  
started shipping built-in FireWire ports, and until this episode had  
never lost a port on either a computer or an external device. But in  
six weeks, I have lost five FireWire 800 ports on three separate two- 
port 2.5" external hard drive cases after using the cases with the FW  
800 ports on several different Power Mac G5 Dual-Core 2.3GHz  
computers. The ports initially work fine, but at some point I plug the  
drive into a computer and the drive volumes do not mount. Switching to  
the case's other port does work, until one day the same fate befalls it.
Bus power still reaches the drive through a bad port, as it spins-up  
normally, but the drive never performs any I/O (based on the case  
light). The drive itself is unaffected by the cases' port failures.  
Not all cases were ever connected to the same Power Mac G5--I'm  
hooking the drives up to new computers for configuration. And prior to  
starting on the Power Mac G5s, I had used the first case with several  
iMac G5s, connecting it via an 800/400 adapter cable. And an old FW  
400 LaCie PocketDrive has been connected to all the same G5s' FW 400  
back ports without any problem.
There are two common factors here. The first is the Power Mac Dual- 
Core G5s. The second is the FireWire interface boards in the external  
drive cases. I have used two different brands of cases (I won't  
mention them because I'm working with their tech support, but will  
note that both readily replaced their failed cases so far). Both  
brands use a board that I'm told is from MacPower with Oxford 912  
chips. (I do not know whether this is the same MacPower that sells its  
own FireWire cases, and they do not appear to offer a 2.5" FW 800  
enclosure.) One brand of case uses version 1.2 of the board and the  
other uses version 2.0. The reason I selected these cases in the first  
place is that the boards/cases have a power on/off switch, which makes  
it easier when temporarily disconnecting the drive, and should also  
reduce the risk of FireWire port damage by reducing the number of  
times a cable needs to be connected/disconnected. I always have the  
cases turned off when connect ing or disconnecting them. I almost  
always have the G5s turned off as well, but they do provide FireWire  
port power even when off--a change from many older models, as someone  
else noted on March 16, and which I suspect may be part of the problem.

To read the complete posting goto: http://www.macintouch.com/readerreports/powermacg5/topic4147.html#d17mar2006
Or you might want to start at: http://www.macintouch.com/readerreports/powermacg5/topic4147.html

Best regards,

Harry
----------------------------------------------------

On Mar 10, 2008, at 5:42 PM, Michele Stapleton wrote:

> Hi Harry,
>
> Thanks for very good suggestions.
>
> Tried each drive one at a time. They will all mount via USB, but none
> will mount via FW.
>
> Resetting PRAM/VRAM didn't make any difference.
>
> Bummer.
>
>
> Michele
>
> -----------------------------------------------
> Michele Stapleton, photographer
> BRUNSWICK, MAINE
> http://www.MicheleStapleton.com
> http://www.MaineWeddingPhotographer.com/
> -----------------------------------------------
>
>
>
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