PowerBook on fire from Firewire Target Disk Mode?!? [Archive]

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jaw04005

Dec 17, 2005, 06:50 PM

pdpfilms

Dec 17, 2005, 07:06 PM

Hey everyone,

I just tried to mount my PowerBook G4 to my PowerMac G5 using Target Disk Mode. I plugged the Firewire cable into the G5, and then into the PowerBook (was preparing to reboot it) and the fans started spinning really loudly. I quickly unplugged the Firewire cable, removed the battery and power adapter, when I noticed smoke coming from where the ports are layed out.

I've turned it on since and it appears to boot only without the battery installed. As of now, the PowerBook has been shut down.

Any idea what could have caused the problem? I'm using an Apple Firewire 6 pin to 6 pin cable. Unfortunately, it's out of warranty.

Update: PowerMac appears to be fine, no sign of any problems. PowerBook still smells like smoke, but is operational and working like normal (minus the battery). S.M.A.R.T. status verified.

Any signs of shortings within the battery? Any scorches in the battery panel? Does the battery light up when you press the indicator button?

CanadaRAM

Dec 17, 2005, 07:08 PM

Hey everyone,

I just tried to mount my PowerBook G4 to my PowerMac G5 using Target Disk Mode. I plugged the Firewire cable into the G5, and then into the PowerBook (was preparing to reboot it) and the fans started spinning really loudly. I quickly unplugged the Firewire cable, removed the battery and power adapter, when I noticed smoke coming from where the ports are layed out.

I've turned it on since and it appears to boot only without the battery installed. As of now, the PowerBook has been shut down.

Any idea what could have caused the problem? I'm using an Apple Firewire 6 pin to 6 pin cable. Unfortunately, it's out of warranty.

Update: PowerMac appears to be fine, no sign of any problems. PowerBook still smells like smoke, but is operational and working like normal (minus the battery). S.M.A.R.T. status verified.

Yup. You plugged the Firewire cabe in upside down or crooked, and shorted the power lines against the data lines.

The Powerbook's Firewire circuits are now crispy critters - they're pooched. Don't know about collateral damage to the battery or the batttery circuits in the PB.

Lucky you didn't take out the G5's as well -- have you tested it with any other firewire peripherals?

Please people: Don't plug and unplug Firewire cables with the machinery on!! This goes for DV cameras and drives as well!!

mjstew33

Dec 17, 2005, 07:12 PM

Please people: Don't plug and unplug Firewire cables with the machinery on!! This goes for DV cameras and drives as well!!
wait... huh? :confused: does this really make a difference?

TheMonarch

Dec 17, 2005, 07:13 PM

...Please people: Don't plug and unplug Firewire cables with the machinery on!! This goes for DV cameras and drives as well!!

What about iPods?

Isin't Firewire supposed to be 'plug and play'/hotswappable anyways?
:confused:

mjstew33

Dec 17, 2005, 07:25 PM

What about iPods?

Isin't Firewire supposed to be 'plug and play'/hotswappable anyways?
:confused:

yeah, that's what i'm confused about

:confused:

mkrishnan

Dec 17, 2005, 07:38 PM

This is the second or third time this concern has come up here about FW hot-swapping. I completely understand the logic, but no one seems to have an answer about the iPod. I have never heard of anyone turning their iBook off or even putting it to sleep in order to plug in an iPod. And you are not instructed by Apple to do so. But the power line is the power line -- the voltage biased for the iPod is the same as it is for any other device. Even if the current draw is higher on some other devices.

adk

Dec 17, 2005, 07:58 PM

First off, how is it even possible to plug in firewire backwards, the plug isn't symmetrical. Second, if this is true, I can see it not mattering with the ipod since the plug going into the ipod is different from regular firewire.

CanadaRAM

Dec 17, 2005, 08:03 PM

What about iPods?
Isin't Firewire supposed to be 'plug and play'/hotswappable anyways?
:confused:
Supposed to be, yes. If Firewire jacks didn't carry 5V buss power, there'd be no issues at all. But they do, so...

The "D" shaped 6-pin Firewire plug is a bad, bad design. One end is | and the other is >, so it looks a bit like |__> . Although it is asymmetrical, there is no other keying -- and the shell of the female jack is lightweight sheet metal that distorts with very little force.

It takes only a little force to accidentally plug it in upside down <__| instead of |__> and when you do, it shorts the 5V lines directly to the data lines. Only takes about 1/4 of a second of this to fry the circuits. (It does not have to be plugged all the way in to contact)

Also, the D shaped female jack's shell is prone to loosening (especially if upside-down plugging has been attempted in the past), allowing the male plug to twist and wiggle - or to make contact at an angle ([\] instead of [|]) when you're plugging in. Again, 1/4 second of joy and you're toasted.

You might think that iPods, (with their different plug) and DV cameras, because they have a 4 pin jack that omits the power pins, are immune. Nope. If you plug in the camera first, and then plug the 6-pin plug into the Mac, you can still short power to data at the Mac end, and fry both the camera and the Mac. (A new Panasonic MiniDV Camera motherboard costs $500, plus $200 labour to install. Ask me how I know...)

You can also fry equipment with a Firewire cable that is kinked or damaged and shorted internally

So the rules.
1) Only ever plug in Firewire cables when both devices are turned off. The exception being a peripheral with a dock or a plug that is designed for repeated insertion. Even then, do not plug/unplug the Mac end of the cable, only the device end.

2) If you must hot-plug, unplug the peripheral from FW, plug FW in the Mac, then plug in the peripheral. Make d@mn sure to plug in with the plug in the correct orientation and lined up properly. DON'T fish around in the dark reaching behind the machine and 'hunting' with the FW plug.

3) If a firewire cable shows any sign of damage -- distorted shell, mashed cable or a kink. THROW IT AWAY. If you accidentally step on the end of a cable, don't bend it back into shape, THROW IT AWAY. (this is a $20 vs $700 choice here, gang. Not worth the risk.)

4) Inspect the female sockets on your equipment - if the shell has "spread" or become distorted, discontinue using that port or have it replaced (this is a problem of course for motherboard mounted ports...)

5) If you must plug and unplug Firewire repeatedly, get a Firewire hub. Let the hub take the wear and tear instead of your machine's ports, and then throw the hub away if the ports get the slightest bit damaged.

Thanks
Trevor
CanadaRAM.com

California

Dec 17, 2005, 08:05 PM

mkrishnan

Dec 17, 2005, 08:11 PM

Trevor, thanks for the info and valuable analysis! :)

CanadaRAM

Dec 17, 2005, 08:16 PM

Sounds like a warranty repair to me. How in heck could someone jam an firewire cable in wrong? You'd break the plug, first of all. Methinks both these units are ready to go in for warranty service. The words "smoke" and "powerbook" in the same sentence? Scary.
Nope. User error all the way.
#1 damage the jack by shoving it in wrong (not warranty)
#2 fry the machine (not warranty)

jaw04005

Dec 17, 2005, 08:44 PM

Upon further analysis, it appears that Firewire cord is slightly bent on one of it's ends. The end was plugged in correctly to the PowerMac G5, but was damaged (was still plugged since the incident). The end that I plugged into my PowerBook does not appear to be damaged.

The PowerBook appears to be working normally as stated above. I have also reinstalled the battery and it booted and now is charging. The smoke smell has cleared. I have plugged the iPod into the PowerBook and it did mount and iTunes opened. So, as of now, it appears it's okay. However, there is no telling what damage was done to the logic board or fan system.

The unit was already out of warranty. I have backed up my data to DVD-Rs and I guess that's the only thing I know to do. I'm sort of worried about using it. I guess it's safe?

Thanks for all the information. That's the last time I plug in a firewire device while the unit is on. I guess I'll USB 2 from now on for my iPods too.

aquajet

Dec 17, 2005, 08:46 PM

Nope. User error all the way.
#1 damage the jack by shoving it in wrong (not warranty)
#2 fry the machine (not warranty)

Well if you read the original post, it seems he inserted the firewire cable correctly, considering it was connected and then he disconnected it after the fans started to spin. Perhaps it was the cable or the PowerBook itself that was defective to begin with. Regardless, this should absolutely be covered by AppleCare (if it wasn't already expired).

Good thing both machines didn't go up in smoke. :(

jaw04005

Dec 17, 2005, 08:49 PM

I should mention that the firewire cable I used remains plugged in all the time. I've used it for printers, portable hard drives and until now, my PowerBook. It's been laying beside my PowerMac for months. From now on, I'll plug and replug when using devices, so that I can inspect the cable's ends.

CanadaRAM

Dec 17, 2005, 08:52 PM

Well if you read the original post, it seems he inserted the firewire cable correctly, considering it was connected and then he disconnected it after the fans started to spin. Perhaps it was the cable or the PowerBook itself that was defective to begin with. Regardless, this should absolutely be covered by AppleCare (if it wasn't already expired).
Good thing both machines didn't go up in smoke. :(
I may be beating a dead horse but according to the original post, the damage occurred immediately that the cable was plugged into the Powerbook. I don't see where the post said that the connection had been made successfully.

Whether it was a damaged cable, a loose FW jack on the PB or incorrect insertion we don't know. But the description is consistent with shorting.
Warranty isn't going to cover a damaged cable or the damage it does to equipment, or incorrect insertion of the plug.

Warranty would cover if the firewire circuitry INSIDE the powerbook spontaneously shorted out, perhaps as a result of a bad solder joint from the factory (and the PB was under warranty of course).

JordanNZ

Dec 19, 2005, 12:36 AM

I fried the firewire on my ti-book by plugging in a cable upside down.. It was actually very easy to do. The port had gradually bent over time, so it slipped right in very easily... A lot of smoke and swearing later.. You get the idea.

Lucky I could buy a PCMCIA usb2/firewire card.

Gokhan

Dec 19, 2005, 09:34 AM

so let me get this right if i want to use my dv camrea with my powerbooks make sure both are turned off then plug in all cables and power up right ??

i have just plugged in a firewire cable into my firewire hub and then to my dv cam before and it was fine what gives ?

also i have my external hd plugged in to my hub all the time and when i want to use i just plug power in to mains is this safe !!!

very concerned after reading this !!

maya

Dec 19, 2005, 12:21 PM

Good lesson, people take it easy when plugging and unplugging the FireWire cable. ;) :)

Jon'sLightBulbs

Dec 19, 2005, 12:58 PM

Because its connectors combust after a simple, common mistake. I'll take my non-constant usb 2.0 transferspeed over this. Good riddance, FW.

Lord Blackadder

Dec 19, 2005, 12:59 PM

Ha, and people said USB 2.0 was inferior....:rolleyes:

It's true though, FireWire cables are far too easy to plug in upside down.

darkwing

Dec 19, 2005, 01:13 PM

Yup. You plugged the Firewire cabe in upside down or crooked, and shorted the power lines against the data lines.

I bet not. I used to do a lot of board level test/repair and I found when this happened, nothing usually gets damaged (unless the line is trying to assert a low for a long period of time, but even then the transistors internal resistance is usually enough to keep it from overheating, especially since the resistance goes up as the temperature goes up.)

The problem described here suggests power was shorted to ground, and the current being pulled through the lines was enough to fry a trace on the board or melt a wire.

agreenster

Dec 19, 2005, 01:55 PM

Why do you think they call it Firewire?

mkrishnan

Dec 21, 2005, 09:13 AM

Wait, now I have another question about shorting the power and data pins on a Firewire cable when plugging it into a computer, that I didn't understand to ask until I read the other thread (http://forums.macrumors.com/showthread.php?t=167932). :o

The PMG5 has hella power, right? And FW is able to provide 45W/cable, which amounts to a lot of current at 5VDC. But in my case, or a lot of our cases, we have puny iBooks or Powerbooks, and there's no way they're providing 45W to anything, since, for instance, my whole iBook runs and charges off a 50W power supply. And iBooks are famous for underpowering their USB connections.

So my question is... is this much of a concern to notebook users? I mean, I know I have to be careful, but even if I did short something, I wonder if my notebook is able to put out the kind of power necessary to do damage via FW to begin with....

Not that it helps the OP; I'm just curious. Sorry. :(

sgmorr

Dec 27, 2005, 06:29 PM

So the rules.
1) Only ever plug in Firewire cables when both devices are turned off. The exception being a peripheral with a dock or a plug that is designed for repeated insertion. Even then, do not plug/unplug the Mac end of the cable, only the device end.

2) If you must hot-plug, unplug the peripheral from FW, plug FW in the Mac, then plug in the peripheral. Make d@mn sure to plug in with the plug in the correct orientation and lined up properly. DON'T fish around in the dark reaching behind the machine and 'hunting' with the FW plug.

3) If a firewire cable shows any sign of damage -- distorted shell, mashed cable or a kink. THROW IT AWAY. If you accidentally step on the end of a cable, don't bend it back into shape, THROW IT AWAY. (this is a $20 vs $700 choice here, gang. Not worth the risk.)

4) Inspect the female sockets on your equipment - if the shell has "spread" or become distorted, discontinue using that port or have it replaced (this is a problem of course for motherboard mounted ports...)

5) If you must plug and unplug Firewire repeatedly, get a Firewire hub. Let the hub take the wear and tear instead of your machine's ports, and then throw the hub away if the ports get the slightest bit damaged.

Thanks
Trevor
CanadaRAM.com
OK, Trevor, I need some advice. I have a peripheral FW HD that I use to maintain a bootable clone of my iMac's internal HD for backup. I update the clone about once per week and don't use my FW HD for anything else (at present). Currently, I keep my FW HD plugged into its power supply and switched off when not in use. When I want to update my clone, I plug the FW cable from the HD into the FW port on my iMac. This causes the HD to "fire up" and mount on my desktop so that I can work with it. After updating my clone, I unmount the FW HD from my desktop, unplug it from my iMac and switch off the FW HD using its power button. Is all of this a safe way of doing things? Thanks.

CanadaRAM

Dec 27, 2005, 06:41 PM

OK, Trevor, I need some advice. I have a peripheral FW HD that I use to maintain a bootable clone of my iMac's internal HD for backup. I update the clone about once per week and don't use my FW HD for anything else (at present). Currently, I keep my FW HD plugged into its power supply and switched off when not in use. When I want to update my clone, I plug the FW cable from the HD into the FW port on my iMac. This causes the HD to "fire up" and mount on my desktop so that I can work with it. After updating my clone, I unmount the FW HD from my desktop, unplug it from my iMac and switch off the FW HD using its power button. Is all of this a safe way of doing things? Thanks.
I'd go ahead with the same technique, but just leave the Firewire cable plugged in 24/7. With the drive power switch off, it is approximately identical to the OS as the drive being unplugged. It's not the powering on that's the problem, it's the inserting and pulling out of the cable.

sgmorr

Dec 27, 2005, 06:46 PM

lucface

Dec 27, 2005, 09:46 PM

Why do you think they call it Firewire?
hahaha, thats great;)

CanadaRAM

Dec 27, 2005, 10:21 PM

The weird thing is, my Iomega 250 GB triple interface HD does not power off unless the FW cable is disconnected. I talked to their tech support and they confirmed this. Seems strange to me.

Edit: I just chatted with Iomega tech support. They said the reason you cannot power off the FW HD while it is still connected to the Mac via the FW cable is that the Mac FW bus stays powered even after the FW HD is unmounted from the desktop. As long as the Mac FW bus is powered, the blue power light stays lit on the FW HD in spite of pressing the power button. They said I must disconnect the FW cable from the Mac in order to power off the Iomega using the power button. So this means having to deal with the various issues of possible misconnection of the FW cables. Oh, well.

In that case I would be tempted to modify a Firewire cable to cut the power lines. Or take it 6pin to 4 pin, then 4 pin to 6 pin, as the 4 pin connector does not have the power leads.

This is just bad design. They din't bother to route the Firewire power leads through the switch. It means if you plug this puppy into a laptop and you think it is turned off, it is still leaching power from your 'book's battery.

Wanna make a bet that damage to the Firewire port from excessive unplugging and plugging isn't covered by warranty? @#^@%

Confirms why I hate iomega.

sgmorr

Dec 27, 2005, 10:38 PM

This is all very interesting Trevor. I appreciate it. So if I use a 6 to 4 and a 4 to 6, there will be no power transfer between the Mac and the Iomega HD?

For future reference, do you know which peripheral FW HDs have power switches that switch off the FW power also?

The more I learn about FW, the less I like it!

Edit: Not that I would want to, but I was told that one should not leave a loose FW cable plugged into a FW port on the Mac. True or not?

bodeh6

Jan 18, 2006, 09:39 AM

I just ordered my FW400 external HD for back up for my iBook and remember reading this about a month ago. Good info. Who knew that when I got a Apple I would become a media freak. Every cool video I see on the net I save, my iTunes collection is growing nicely, photos from my sisters wedding weigh in at over 3 gigs alone (they are all I believe 8 megapixels or so from a professional photographer) and lets not forget about all the other pics I have.

Mac OS X Tiger with iTunes, iPhoto, and Quicktime really do make people use their compters to do more purposeful work then Windows XP. It's because it is all so easy to handle different media on Mac OS X then Windows.