PowerBook on fire from Firewire Target Disk Mode?!?

Discussion in 'PowerPC Macs' started by jaw04005, Dec 17, 2005.

  1. macrumors 601

    jaw04005

    Joined:
    Aug 19, 2003
    Location:
    AR
    #1
    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.
     
  2. macrumors 68020

    pdpfilms

    Joined:
    Jun 29, 2004
    Location:
    Vermontana
    #2
    Any signs of shortings within the battery? Any scorches in the battery panel? Does the battery light up when you press the indicator button?
     
  3. macrumors G5

    CanadaRAM

    Joined:
    Oct 11, 2004
    Location:
    On the Left Coast - Victoria BC Canada
    #3
    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!!
     
  4. macrumors 601

    mjstew33

    Joined:
    May 29, 2005
    Location:
    Illinois
    #4
    wait... huh? :confused: does this really make a difference?
     
  5. macrumors 65816

    TheMonarch

    Joined:
    May 6, 2005
    Location:
    Bay Area
    #5
    What about iPods?


    Isin't Firewire supposed to be 'plug and play'/hotswappable anyways?
    :confused:
     
  6. macrumors 601

    mjstew33

    Joined:
    May 29, 2005
    Location:
    Illinois
    #6
    yeah, that's what i'm confused about

    :confused:
     
  7. Moderator emeritus

    mkrishnan

    Joined:
    Jan 9, 2004
    Location:
    Grand Rapids, MI, USA
    #7
    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.
     
  8. adk
    macrumors 68000

    adk

    Joined:
    Nov 11, 2005
    Location:
    Stuck in the middle with you
    #8
    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.
     
  9. macrumors G5

    CanadaRAM

    Joined:
    Oct 11, 2004
    Location:
    On the Left Coast - Victoria BC Canada
    #9
    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
     
  10. macrumors 68040

    California

    Joined:
    Aug 21, 2004
    #10
    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.
     
  11. Moderator emeritus

    mkrishnan

    Joined:
    Jan 9, 2004
    Location:
    Grand Rapids, MI, USA
    #11
    Trevor, thanks for the info and valuable analysis! :)
     
  12. macrumors G5

    CanadaRAM

    Joined:
    Oct 11, 2004
    Location:
    On the Left Coast - Victoria BC Canada
    #12
    Nope. User error all the way.
    #1 damage the jack by shoving it in wrong (not warranty)
    #2 fry the machine (not warranty)
     
  13. thread starter macrumors 601

    jaw04005

    Joined:
    Aug 19, 2003
    Location:
    AR
    #13
    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.
     
  14. macrumors 68020

    Joined:
    Feb 12, 2005
    Location:
    VA
    #14
    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. :(
     
  15. thread starter macrumors 601

    jaw04005

    Joined:
    Aug 19, 2003
    Location:
    AR
    #15
    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.
     
  16. macrumors G5

    CanadaRAM

    Joined:
    Oct 11, 2004
    Location:
    On the Left Coast - Victoria BC Canada
    #16
    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).
     
  17. macrumors 6502

    Joined:
    Apr 29, 2004
    Location:
    Auckland, New Zealand
    #17
    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.
     
  18. macrumors 6502a

    Joined:
    Oct 7, 2003
    Location:
    London
    #18
    so

    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 !!
     
  19. macrumors 68040

    maya

    Joined:
    Oct 7, 2004
    Location:
    somewhere between here and there.
    #19
    Good lesson, people take it easy when plugging and unplugging the FireWire cable. ;) :)
     
  20. macrumors 6502a

    Joined:
    Jan 31, 2005
    Location:
    Chicago
    #20
    Apple is abandoning Firewire why, again?

    Because its connectors combust after a simple, common mistake. I'll take my non-constant usb 2.0 transferspeed over this. Good riddance, FW.
     
  21. macrumors G4

    Lord Blackadder

    Joined:
    May 7, 2004
    Location:
    Sod off
    #21
    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.
     
  22. macrumors 65816

    Joined:
    Jan 6, 2004
    #22
    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.
     
  23. macrumors 68000

    agreenster

    Joined:
    Dec 6, 2001
    Location:
    Walt Disney Animation Studios
    #23
    Why do you think they call it Firewire?
     
  24. Moderator emeritus

    mkrishnan

    Joined:
    Jan 9, 2004
    Location:
    Grand Rapids, MI, USA
    #24
    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. :eek:

    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. :(
     
  25. macrumors member

    Joined:
    Nov 13, 2005
    Location:
    DFW area Texas
    #25
    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.
     

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