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You are here: MacNN Forums > Hardware - Troubleshooting and Discussion > Mac Desktops > 2007 iMac - Firewire 800 Port Looks Dead

2007 iMac - Firewire 800 Port Looks Dead
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ghporter
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Oct 8, 2012, 02:42 AM
 
Out of the blue, my Firewire 800 port seems to have stopped working. I had it connected to an external drive, and yesterday I noticed that the drive wasn't mounted, so I looked into it. The drive works, and it's now connected via USB (obviously much slower), and so I investigated further. With limited Firewire 800 hardware on hand, I seem to have proven to myself that the port is dead. How should I go about testing more fully? I have not had any diagnostic tools since I moved up to Snow Leopard, at least I don't think the tools that came with Leopard will work with SL. Any help would be appreciated.

Glenn -----OTR/L, MOT, Tx
     
Thorzdad
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Oct 8, 2012, 04:54 AM
 
Are you sure it's the port on the iMac and not the FW800 port on whatever enclosure/dock you had the drive mounted in?

I had been using a drive mounted in a NewerTech Voyager drive dock to back-up mydaughter's older MacBook using the FW400 connection. It worked once, then it no longer worked. After trying a couple of cables, I assumed the problem was with her MacBook. But, she took the MacBook to an Apple Store and they hooked-up the MacBook to a FW400 drive and it worked perfectly. So, apparently, the FW400 port on the dock is faulty.
     
P
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Oct 8, 2012, 04:57 AM
 
The only software tool I know of that will diagnose Firewire ports is Techtool Pro.

I know that historically Firewire ports usually failed when the drive tried to pull more power than the port was designed to deliver, which meant that the port would still work as an unpowered port, but I haven't heard anything about that in models as recent as 2007.
The new Mac Pro has up to 30 MB of cache inside the processor itself. That's more than the HD in my first Mac. Somehow I'm still running out of space.
     
ghporter  (op)
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Oct 9, 2012, 02:45 AM
 
The port does not work with the drive, and it does not work with a FW800 Express Card in my MBP (it not show "connected" at either end). I have used two different cables, and the Express Card works fine with FW400. The external drive is powered externally, so that shouldn't be an issue.

Techtool Pro costs $100... I don't know if I can justify that. I wonder how much a Genius Bar visit for a 5 year old iMac will cost.

Glenn -----OTR/L, MOT, Tx
     
Waragainstsleep
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Oct 9, 2012, 03:38 AM
 
What does System profiler say? Sometimes it will tell you a firewire port is dead.
I have plenty of more important things to do, if only I could bring myself to do them....
     
hayesk
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Oct 9, 2012, 09:58 AM
 
Mine went dead once too. Here's what I did.

Shut down iMac.
Unplug cord. (really, I had to do this step)
Wait half an hour or more.
Start up iMac again.

That's it. I've owned this iMac (mid 2007) since I bought it new and I've only had to do that once.
     
barryjaylevine
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Oct 9, 2012, 10:30 AM
 
I also have an OWC dock with a bad (loose-fitting) FW400 port. I have two of these docks and only one seems to have the bad port. I'll RMA it this week.
     
seanc
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Oct 9, 2012, 11:17 AM
 
Originally Posted by hayesk View Post
Mine went dead once too. Here's what I did.
Shut down iMac.
Unplug cord. (really, I had to do this step)
Wait half an hour or more.
Start up iMac again.
That's it. I've owned this iMac (mid 2007) since I bought it new and I've only had to do that once.
This.

Except for the unplug for half an hour part, just hold the power button in for about a minute.

Works on PCs when the onboard networking can no longer detect any connection - might well work for this.
     
Nigbo
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Oct 9, 2012, 12:59 PM
 
Do an SMC Reset

Shut down your Mac
Plugin to electric power
Press Shift-Ctrl-Option + Power
Nothing visible happens!
Then press the power key solo to restart
FireWire will be available again
     
msuper69
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Oct 10, 2012, 09:28 AM
 
"Firewire 800 Port Looks Dead" - Could be a headline for the future of ALL Firewire 800 ports.

Hope you get yours working again.
     
D R Turbo
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Oct 16, 2012, 12:48 AM
 
This is my first day on this web site, and I'm ending up referencing the same stuff I had in another post. Download the book on hard drive troubleshooting here:

http://scsc-online.com/Downloads.html

I don't remember the exact words, but I think the book essentially said the FireWire physical interface chip is somewhat notorious for blowing. I've seen this happen on several units, and interestingly, Apple's hardware test and TechTools pro won't recognize it. I think the reason is that the output stages of the interface chip can blow from a transient, and the drivers are analog, not digital. The digital portion of the interface works OK, which is why AHD says it's OK, but the analog drivers are gone. Test tools won't recognize this problem (none of them will, not even Scannerz) because FireWire ports were intended to be removable, and if the output stages are blown, as far as the OS and any tools are concerned, nothing is plugged into them.

On an old PowerBook G4 that had this problem, if you plugged a self powered drive into the port, it would power up and look like it's there, but the system wouldn't recognize the drive at all. It wouldn't even show up on Disk Utility as a drive. The reason is that the supply lines feeding the drive are not going through the interface chips analog drivers.

There are actually a few web posts on this problem if you do a Google search. One guy actually managed to replace it, but the soldering expertise or tricks, if you will, is beyond my capabilities. Gone are the days of pulling out your soldering iron and replacing chips.

With all that said, I guess I can only conclude, "Welcome to club FireWire."
     
Spheric Harlot
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Oct 16, 2012, 01:52 AM
 
What does a defective fw 800 port have to do with your hard drive troubleshooting guide, whose purpose AFAICT is to recommend the other software tools you offer for download on that page?


Edit: oh. Pity. Post was flagged as spam (which it was). It did contain salient information, though.
     
ZVH2012
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Oct 17, 2012, 10:18 AM
 
Since when is the only guy that answered the question properly a spammer? I noticed the other night he made two posts, both about hard drives, and referenced a free book.

Most spammers, guys, don't provide actual answers to questions, they just put up crap and tell everyone how they need to rush out and buy whatever is they're trying to push. I didn't see any of that in the guys post. Deleting that post was hyper paranoia run amok.

I came back to reference it and was hoping to ask that guy some questions, but now the post is gone...and I bet he is too.

FWIW, what he was talking about was failure of what's called the FireWire PHY chip. Here are some references to the problem, and what he was saying appeared to be correct;

http://www.medicalmac.com/mac98e.html
http://reviews.cnet.com/8301-13727_7-10342214-263.html

A quote from the latter:

"Bus powering defects In some cases, FireWire failure can be the result of manufactures' inability to use bus power correctly per design specs. Poor bridge design can overload or short the FireWire port, rendering it unusable for data transfer, but still viable for powering devices."

That sounds EXACTLY like what that guy was talking about.

Guys, if you're going to kill posts for spamming, please make sure it's REAL spamming, and not some guy that's all excited because some company put a book out on the web that's free and apparently a good read. I came back here hoping to get the link to the book and now it's gone.
     
reader50
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Oct 17, 2012, 11:55 AM
 
D R Turbo, thanks for pointing that out. Normally, a protest to the site admins will get a review, but our contact link isn't working at present. Even I don't know where it goes. I tried sending a couple test messages to it, and never heard anything back.

Your post followed a real spam post, and a link to a paid product site looks suspicious.

Your ban is lifted, and your missing posts restored. Welcome to our humble abode.
     
ZVH2012
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Oct 17, 2012, 02:15 PM
 
D R Turbo:

Do you have a link or links to the site where the guy replaced his FireWire chip?

Thanks.

P.S. And thanks to the moderator for restoring the D R Turbo post.
     
Spheric Harlot
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Oct 17, 2012, 05:22 PM
 
Originally Posted by ZVH2012 View Post
FWIW, what he was talking about was failure of what's called the FireWire PHY chip. Here are some references to the problem, and what he was saying appeared to be correct;

http://www.medicalmac.com/mac98e.html
http://reviews.cnet.com/8301-13727_7-10342214-263.html

A quote from the latter:

"Bus powering defects In some cases, FireWire failure can be the result of manufactures' inability to use bus power correctly per design specs. Poor bridge design can overload or short the FireWire port, rendering it unusable for data transfer, but still viable for powering devices."

That sounds EXACTLY like what that guy was talking about.
I know somebody whose titanium PowerBook was affected by that problem (three times), and my iMac DV's FireWire PHY died twice.

That issue was fixed on all machines shipped or repaired by Apple after June 25, 2002, as per the medicalmac link you posted.

Apple finally changed the overload protection to match their own damn spec at that point.



Originally Posted by ZVH2012 View Post
Guys, if you're going to kill posts for spamming, please make sure it's REAL spamming, and not some guy that's all excited because some company put a book out on the web that's free and apparently a good read. I came back here hoping to get the link to the book and now it's gone.
FWIW, the page has a link to the book (which is off-topic wrt this thread), and a bunch of download links for maintenance tools, which I assume are commercial, and which also have nothing to do with the subject of this thread.

I didn't report the post as spam, because it was relevant and salient, but including that information in an otherwise completely unrelated post does qualify as spam. Stick it in the signature, and it doesn't.
     
D R Turbo
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Oct 17, 2012, 11:31 PM
 
Spheric Harlot:

The day I did the original post, I made two posts, both about hard drives, and in both I provided the link to the book. It occurred to me this might look like spam, but the book is free and I was providing answers, so I posted them anyway. I posted the reference to the book because it covers hard drives from a systems standpoint, not just the hard drive as a single entity.

Is the book an indirect ad for that companies products? Of course it is. So what? It's still free, and it contains information not only about the FireWire PHY port, but also what they call "complete and intermittent generic faults" which are actually an assortment of mechanical defects (complete and intermittent losses of electrical contact) in circuit boards, connectors, and cables. One common fault it cites is the fact that external units, both USB and FireWire, can be subjected to mechanical failure (as in breaks, complete or intermittent) due to lateral impact. The length of a protruding connector essentially acts like a lever with the physical connectors connecting the port to the logic board taking the brunt of impact if bumped, thus completely breaking them or cracking them. If a FireWire port goes bad, these, along with PHY chip failure are probably all equally likely suspects. I learned this all from that book and didn't need to buy a product to get it.

IMHO, the book is clearly beyond the scope of average users and is likely targeting technicians. The section on external drives is directly applicable to this thread. If the book is too technical for a given reader, it was free. All it cost them was the time to download it.

ZVH2012:

The link to the actual PHY chip replacement is here:

http://www.hardmac.com/articles/16/page1


It has 4 pages, with page 4 actually showing the installation of the replacement chip. Some things you need to be aware of:

1. The chip looks a lot bigger in the photos than it is. The actual chip is about 1/4 inch by 1/4 inch. The pictures make it look like it might be about 1/2 inch by 1/2 inch.

2. They're doing that on an old Titanium, which bridges the FireWire to ATA. Newer systems obviously won't use that.

I personally wouldn't attempt a repair like that on any system that was worth anything because I think the odds of inflicting damage are probably every bit as high as actually fixing the unit. There is actual equipment designed to repair such boards, but it's typically thousands (possibly tens of thousands) of dollars. Most systems will run with a blown FireWire PHY chip or one with cracked or broken connectors to the outside world, but if you end up damaging another component in the process, then the whole system is lost.

The "trick" used by those that created that report seems to be to load a solder wick up with solder and then run the iron across the wick and let the solder flow down into the gaps between the circuit board and the IC connectors. I would think the odds of bridging the IC pins are as high as actually succeeding, which would mean numerous attempts before success is achieved. How many times can the IC be subjected to so many radical variations in temperature before it itself becomes damaged? During all this, you also need to ensure the chips pins are lined up with those on the circuit board. A lot of this work needs to be done with high magnification as well. I've seen some videos on YouTube of guys actually doing this tactic on other circuit boards (not Macs), and my only conclusion was "better you than me."

I wouldn't assume that a PHY chip is blown just because a port isn't working - it's just a possibility to be considered. If you went through all that effort and then found out the problem was elsewhere, you'd just end up wasting your time and possibly busting a system in the process as well. Several of the other resets some of the others have posted are pertinent as well.

Just my opinions.
     
Spheric Harlot
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Oct 18, 2012, 06:12 AM
 
Apologies; I see you meant no harm.

I was in fact not the one who reported your post as spam, having given you the benefit of the doubt for your very informative post.

I'm glad to see you return and hope you'll continue to grace these forums with your technical expertise.


In any case:


There's a reason that they're doing that on a titanium PowerBook, as I've mentioned twice:

No machine shipped later than June 2002 is affected by that particular issue.

It simply hasn't been relevant for ten years, and certainly does not apply to the 2007 iMac in question, here.
     
D R Turbo
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Oct 18, 2012, 01:48 PM
 
I recognize that the problem existed on the Titaniums, but that doesn't mean the PHY (or any other chip on a logic board) is infallible. Theoretically, you should be able to plug in and remove removable devices at will without problems, but in reality if the ground potential of the device being plugged in and that of the computer are different, the result will be a transient. Depending on the magnitude of the transient, damage may be quite possible, regardless of the degree of protection in the circuit.

Here's a link containing more information than most likely care to read about FireWire failures:

http://www.wiebetech.com/whitepapers/FireWirePortFailures.php
     
ZVH2012
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Oct 19, 2012, 11:44 AM
 
Thanks guys. Enough information in this post to pretty much answer anything about FireWire problems.
     
   
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