Re: Charging devices from Computer USB ports Additional comments on iPhone and iPad charging [was Re: A USB device is drawing too much power]
Hi, Yeah, I'll definitely give that one I shot. I thought I recognized it from something you had to do on occasion with ThinkPad. Again, thanks. I'll let you know. Regards, Nic Mobile Me: nic2...@me.com Skype: Kvalme MSN Messenger: nico...@home3.gvdnet.dk AIM: cincinster yahoo Messenger: cin368 Facebook Profile My Twitter On May 7, 2010, at 2:33 AM, Esther wrote: Hi Nic, I've never used resetting the PRAM to fix a USB port issue before on a Mac -- only used it for audio sound repairs. However, the part about removing a battery and holding down the power button with the battery out (to discharge the capacitor) is something I've had to do before with an IBM ThinkPad laptop to reset electronic components. So that may work in your case, too. HTH Cheers, Esther Nicolai Svendsen wrote: Hi Esther, Thank you. I'll try this. Resetting the PRAM has been tried before, but I'm supposing holding down the power button when battery is removed is some sort of cycle? I'll add it to resetting the PRAM again and let you know how it works out. Regards, Nic Mobile Me: nic2...@me.com Skype: Kvalme MSN Messenger: nico...@home3.gvdnet.dk AIM: cincinster yahoo Messenger: cin368 Facebook Profile My Twitter On May 7, 2010, at 2:18 AM, Esther wrote: Hi Nic, I'll cc this to the viphone list, since the last part of this post is about USB power usage and charging for the iPhone, iPod Touch and iPad. I'm not sure I qualify with respect to knowing a lot about hardware, USB devices, and electricity, but I'll try to answer your question, although I've never had OS X shut a device down with a message that it was drawing too much power. However, I did just make a recent trip where I had to troubleshoot one of the USB ports of a MacBook. Devices that were plugged into that port didn't work properly: printer cables wouldn't relay signals to the attached peripheral, iPods would not be recognized by iTunes, and a plugged in mouse was evidently powered (lit up), but not enough to register clicks on the machine. All these devices worked correctly when plugged into the other USB port. Power cycling with restart and repairing permissions didn't help. (I only tried the permissions repair because the Software Update had just been run to install a security update before the problem behavior.) What did work was resetting the PRAM, which apparently restored the USB port to its full power. If the source of your problem is not the aging of your headphones but the USB current support from your computer, this fix might help. I'll give you the instructions I received from Apple's Tech Support, since they're slightly different from what is in the Knowledge Base article. 1. Power down the computer and remove the battery from the MacBook. (On my model you need to get a thick coin, like a U.S. nickel, to insert in the slot of the lock for the battery, and give it a quarter turn clockwise to rotate it into the unlock position so the side of the battery near the lock will pop up, and so that the battery can be removed.) 2. With the battery removed, hold down the power button for at least 12 seconds. 3. Replace the battery. (On my model, you insert the side near the left edge of the laptop so that it engages, and then swing the other end so that it slots into the lock position. Then you use the coin to turn the slotted lock a quarter turn counter-clockwise to lock again.) 4. Hold down the Command, Option, P, and R keys while you power on your laptop. I press down the Command, Option, and R keys with my left hand (little finger on the Option key, ring finger on the Command key, and either middle or index finger on the R key). I press the thumb of my right hand on the P key and push down on the power button with the middle finger of my right hand. 5. You need to keep the Command, Option, P, and R keys pressed for at least 3 start-up chimes before releasing them in order to reset the PRAM. 6. Log in as usual and check your USB port connections. This fixed all the problems with the USB ports. I think, because the mouse was being powered, but not enough to register clicks with the system, that full power wasn't going to one of the USB ports. I'll point you to the Apple Knowledge Base article on Apple Computers: Powering a peripheral through USB: http://support.apple.com/kb/HT4049 Computer USB 2 ports are supposed to be rated for 500 mAH. That's less than the 1000 mAH you'll get from an AC outlet (in the U.S.) with a USB charger for the iPhone or iPod Touch, which is why charging your device on the computer's USB port is slower, and which is also why the earlier iPods and iPhones could charge from FireWire connectors that didn't have the same limitation. Apple shifted the standard connector for its iPods and iPhones to USB2 because most Windows computers didn't have FireWire (a.k.a. IEEE
Re: Charging devices from Computer USB ports Additional comments on iPhone and iPad charging [was Re: A USB device is drawing too much power]
Hi, Hmm. It won't let me reset the PRAM. Back to the chalkboard. In fact, nothing happens. Every time I reset the PRAM, I have always been holding them down before powering on, and it has always worked. I've tried it ten times now. #Fail# I suppose that is out of the question right now doing that. Regards, Nic Mobile Me: nic2...@me.com Skype: Kvalme MSN Messenger: nico...@home3.gvdnet.dk AIM: cincinster yahoo Messenger: cin368 Facebook Profile My Twitter On May 7, 2010, at 9:23 AM, Nicolai Svendsen wrote: Hi, Yeah, I'll definitely give that one I shot. I thought I recognized it from something you had to do on occasion with ThinkPad. Again, thanks. I'll let you know. Regards, Nic Mobile Me: nic2...@me.com Skype: Kvalme MSN Messenger: nico...@home3.gvdnet.dk AIM: cincinster yahoo Messenger: cin368 Facebook Profile My Twitter On May 7, 2010, at 2:33 AM, Esther wrote: Hi Nic, I've never used resetting the PRAM to fix a USB port issue before on a Mac -- only used it for audio sound repairs. However, the part about removing a battery and holding down the power button with the battery out (to discharge the capacitor) is something I've had to do before with an IBM ThinkPad laptop to reset electronic components. So that may work in your case, too. HTH Cheers, Esther Nicolai Svendsen wrote: Hi Esther, Thank you. I'll try this. Resetting the PRAM has been tried before, but I'm supposing holding down the power button when battery is removed is some sort of cycle? I'll add it to resetting the PRAM again and let you know how it works out. Regards, Nic Mobile Me: nic2...@me.com Skype: Kvalme MSN Messenger: nico...@home3.gvdnet.dk AIM: cincinster yahoo Messenger: cin368 Facebook Profile My Twitter On May 7, 2010, at 2:18 AM, Esther wrote: Hi Nic, I'll cc this to the viphone list, since the last part of this post is about USB power usage and charging for the iPhone, iPod Touch and iPad. I'm not sure I qualify with respect to knowing a lot about hardware, USB devices, and electricity, but I'll try to answer your question, although I've never had OS X shut a device down with a message that it was drawing too much power. However, I did just make a recent trip where I had to troubleshoot one of the USB ports of a MacBook. Devices that were plugged into that port didn't work properly: printer cables wouldn't relay signals to the attached peripheral, iPods would not be recognized by iTunes, and a plugged in mouse was evidently powered (lit up), but not enough to register clicks on the machine. All these devices worked correctly when plugged into the other USB port. Power cycling with restart and repairing permissions didn't help. (I only tried the permissions repair because the Software Update had just been run to install a security update before the problem behavior.) What did work was resetting the PRAM, which apparently restored the USB port to its full power. If the source of your problem is not the aging of your headphones but the USB current support from your computer, this fix might help. I'll give you the instructions I received from Apple's Tech Support, since they're slightly different from what is in the Knowledge Base article. 1. Power down the computer and remove the battery from the MacBook. (On my model you need to get a thick coin, like a U.S. nickel, to insert in the slot of the lock for the battery, and give it a quarter turn clockwise to rotate it into the unlock position so the side of the battery near the lock will pop up, and so that the battery can be removed.) 2. With the battery removed, hold down the power button for at least 12 seconds. 3. Replace the battery. (On my model, you insert the side near the left edge of the laptop so that it engages, and then swing the other end so that it slots into the lock position. Then you use the coin to turn the slotted lock a quarter turn counter-clockwise to lock again.) 4. Hold down the Command, Option, P, and R keys while you power on your laptop. I press down the Command, Option, and R keys with my left hand (little finger on the Option key, ring finger on the Command key, and either middle or index finger on the R key). I press the thumb of my right hand on the P key and push down on the power button with the middle finger of my right hand. 5. You need to keep the Command, Option, P, and R keys pressed for at least 3 start-up chimes before releasing them in order to reset the PRAM. 6. Log in as usual and check your USB port connections. This fixed all the problems with the USB ports. I think, because the mouse was being powered, but not enough to register clicks with the system, that full power wasn't going to one of the USB ports. I'll point you to the Apple Knowledge Base article on Apple Computers: Powering a peripheral through USB: http://support.apple.com/kb/HT4049
A USB device is drawing too much power
Hi guys, So, I'm looking for someone here who knows a lot about hardware, specifically on the Mac-side and someone who knows a lot in particular about USB-devices. Oh, and electricity, perhaps. Here's the deal. I've got a Skype Wireless Freetalk Headset, the old model. I've been using it for a while with no issues at all. Eventually, my Mac would disable the device because it said it was drawing too much power and had to be disabled. The headset setup consist of a round-shaped small box with one button to turn off the receiver completely, and to pair it properly to the receiver and the headset. On this box there are two buttons, one extending to the plug of a USB and the other extending to a small, round plug which plugs into the right side of the headset for charging. Both of these aforementioned wires both extend away from the round box. When I get the message above in a dialog box, the headset promptly turns off because there is no signal being received from the USB port as it becomes disabled, and when touching the wire charging the headset, it becomes boiling hot. The USB wire feels fine, but all the way from the point from which the wire to the charger extends, to the plug that goes into the headset for charging, becomes incredibly hot and almost impossible to touch. My question to those knowing about this type of issue is this: Why would this happen after a year or so of using this headset just fine? Is it because the wire is broken? If that is the case, why could I use it for a couple of hours prior to this happening today, regardless of twisted the wire became? Thanks, and I'd be grateful for any advice. Regards, Nic Mobile Me: nic2...@me.com Skype: Kvalme MSN Messenger: nico...@home3.gvdnet.dk AIM: cincinster yahoo Messenger: cin368 Facebook Profile My Twitter -- You received this message because you are subscribed to the Google Groups MacVisionaries group. To post to this group, send email to macvisionar...@googlegroups.com. To unsubscribe from this group, send email to macvisionaries+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/macvisionaries?hl=en.
Re: A USB device is drawing too much power
I had the same issue for a long time. If your headset is old, it's likely the drivers are not working well with your system. Simple solution, get a new headset. On 6 May 2010, at 22:37, Nicolai Svendsen wrote: Hi guys, So, I'm looking for someone here who knows a lot about hardware, specifically on the Mac-side and someone who knows a lot in particular about USB-devices. Oh, and electricity, perhaps. Here's the deal. I've got a Skype Wireless Freetalk Headset, the old model. I've been using it for a while with no issues at all. Eventually, my Mac would disable the device because it said it was drawing too much power and had to be disabled. The headset setup consist of a round-shaped small box with one button to turn off the receiver completely, and to pair it properly to the receiver and the headset. On this box there are two buttons, one extending to the plug of a USB and the other extending to a small, round plug which plugs into the right side of the headset for charging. Both of these aforementioned wires both extend away from the round box. When I get the message above in a dialog box, the headset promptly turns off because there is no signal being received from the USB port as it becomes disabled, and when touching the wire charging the headset, it becomes boiling hot. The USB wire feels fine, but all the way from the point from which the wire to the charger extends, to the plug that goes into the headset for charging, becomes incredibly hot and almost impossible to touch. My question to those knowing about this type of issue is this: Why would this happen after a year or so of using this headset just fine? Is it because the wire is broken? If that is the case, why could I use it for a couple of hours prior to this happening today, regardless of twisted the wire became? Thanks, and I'd be grateful for any advice. Regards, Nic Mobile Me: nic2...@me.com Skype: Kvalme MSN Messenger: nico...@home3.gvdnet.dk AIM: cincinster yahoo Messenger: cin368 Facebook Profile My Twitter -- You received this message because you are subscribed to the Google Groups MacVisionaries group. To post to this group, send email to macvisionar...@googlegroups.com. To unsubscribe from this group, send email to macvisionaries+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/macvisionaries?hl=en. -- You received this message because you are subscribed to the Google Groups MacVisionaries group. To post to this group, send email to macvisionar...@googlegroups.com. To unsubscribe from this group, send email to macvisionaries+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/macvisionaries?hl=en.
Re: A USB device is drawing too much power
the headset getting hot worries me. I don't kpw anything about electricioty or drivers but have you contacted the company to see if they an give you advice? On May 6, 2010, at 4:06 PM, Nicolai Svendsen wrote: Hi, I'd like to think that was the issue, if I haven't used SNow Leopard with it just fine as well. The thing that makes it look odd as well is that I can use it for some time when I haven't used it in a while. DOing all kinds of stuff with the wire would usually show where the broken part is, but nothing happens. It might be the driver, but I wonder how they got outdated. I'm almost tempted to go back to OS X 10.6.0 to see if that might be the case, as it is a preinstalled driver. Regards, Nic Mobile Me: nic2...@me.com Skype: Kvalme MSN Messenger: nico...@home3.gvdnet.dk AIM: cincinster yahoo Messenger: cin368 Facebook Profile My Twitter On May 7, 2010, at 1:00 AM, marie Howarth wrote: I had the same issue for a long time. If your headset is old, it's likely the drivers are not working well with your system. Simple solution, get a new headset. On 6 May 2010, at 22:37, Nicolai Svendsen wrote: Hi guys, So, I'm looking for someone here who knows a lot about hardware, specifically on the Mac-side and someone who knows a lot in particular about USB-devices. Oh, and electricity, perhaps. Here's the deal. I've got a Skype Wireless Freetalk Headset, the old model. I've been using it for a while with no issues at all. Eventually, my Mac would disable the device because it said it was drawing too much power and had to be disabled. The headset setup consist of a round-shaped small box with one button to turn off the receiver completely, and to pair it properly to the receiver and the headset. On this box there are two buttons, one extending to the plug of a USB and the other extending to a small, round plug which plugs into the right side of the headset for charging. Both of these aforementioned wires both extend away from the round box. When I get the message above in a dialog box, the headset promptly turns off because there is no signal being received from the USB port as it becomes disabled, and when touching the wire charging the headset, it becomes boiling hot. The USB wire feels fine, but all the way from the point from which the wire to the charger extends, to the plug that goes into the headset for charging, becomes incredibly hot and almost impossible to touch. My question to those knowing about this type of issue is this: Why would this happen after a year or so of using this headset just fine? Is it because the wire is broken? If that is the case, why could I use it for a couple of hours prior to this happening today, regardless of twisted the wire became? Thanks, and I'd be grateful for any advice. Regards, Nic Mobile Me: nic2...@me.com Skype: Kvalme MSN Messenger: nico...@home3.gvdnet.dk AIM: cincinster yahoo Messenger: cin368 Facebook Profile My Twitter -- You received this message because you are subscribed to the Google Groups MacVisionaries group. To post to this group, send email to macvisionar...@googlegroups.com. To unsubscribe from this group, send email to macvisionaries+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/macvisionaries?hl=en. -- You received this message because you are subscribed to the Google Groups MacVisionaries group. To post to this group, send email to macvisionar...@googlegroups.com. To unsubscribe from this group, send email to macvisionaries+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/macvisionaries?hl=en. -- You received this message because you are subscribed to the Google Groups MacVisionaries group. To post to this group, send email to macvisionar...@googlegroups.com. To unsubscribe from this group, send email to macvisionaries+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/macvisionaries?hl=en. -- You received this message because you are subscribed to the Google Groups MacVisionaries group. To post to this group, send email to macvisionar...@googlegroups.com. To unsubscribe from this group, send email to macvisionaries+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/macvisionaries?hl=en.
Charging devices from Computer USB ports Additional comments on iPhone and iPad charging [was Re: A USB device is drawing too much power]
Hi Nic, I'll cc this to the viphone list, since the last part of this post is about USB power usage and charging for the iPhone, iPod Touch and iPad. I'm not sure I qualify with respect to knowing a lot about hardware, USB devices, and electricity, but I'll try to answer your question, although I've never had OS X shut a device down with a message that it was drawing too much power. However, I did just make a recent trip where I had to troubleshoot one of the USB ports of a MacBook. Devices that were plugged into that port didn't work properly: printer cables wouldn't relay signals to the attached peripheral, iPods would not be recognized by iTunes, and a plugged in mouse was evidently powered (lit up), but not enough to register clicks on the machine. All these devices worked correctly when plugged into the other USB port. Power cycling with restart and repairing permissions didn't help. (I only tried the permissions repair because the Software Update had just been run to install a security update before the problem behavior.) What did work was resetting the PRAM, which apparently restored the USB port to its full power. If the source of your problem is not the aging of your headphones but the USB current support from your computer, this fix might help. I'll give you the instructions I received from Apple's Tech Support, since they're slightly different from what is in the Knowledge Base article. 1. Power down the computer and remove the battery from the MacBook. (On my model you need to get a thick coin, like a U.S. nickel, to insert in the slot of the lock for the battery, and give it a quarter turn clockwise to rotate it into the unlock position so the side of the battery near the lock will pop up, and so that the battery can be removed.) 2. With the battery removed, hold down the power button for at least 12 seconds. 3. Replace the battery. (On my model, you insert the side near the left edge of the laptop so that it engages, and then swing the other end so that it slots into the lock position. Then you use the coin to turn the slotted lock a quarter turn counter-clockwise to lock again.) 4. Hold down the Command, Option, P, and R keys while you power on your laptop. I press down the Command, Option, and R keys with my left hand (little finger on the Option key, ring finger on the Command key, and either middle or index finger on the R key). I press the thumb of my right hand on the P key and push down on the power button with the middle finger of my right hand. 5. You need to keep the Command, Option, P, and R keys pressed for at least 3 start-up chimes before releasing them in order to reset the PRAM. 6. Log in as usual and check your USB port connections. This fixed all the problems with the USB ports. I think, because the mouse was being powered, but not enough to register clicks with the system, that full power wasn't going to one of the USB ports. I'll point you to the Apple Knowledge Base article on Apple Computers: Powering a peripheral through USB: http://support.apple.com/kb/HT4049 Computer USB 2 ports are supposed to be rated for 500 mAH. That's less than the 1000 mAH you'll get from an AC outlet (in the U.S.) with a USB charger for the iPhone or iPod Touch, which is why charging your device on the computer's USB port is slower, and which is also why the earlier iPods and iPhones could charge from FireWire connectors that didn't have the same limitation. Apple shifted the standard connector for its iPods and iPhones to USB2 because most Windows computers didn't have FireWire (a.k.a. IEEE 1394) ports. This is the source of some of the battery charging error messages that are seen with some iPhone cases -- all devices are now supposed to use chargers that adhere to the more limited current capacities for the USB2 standard. This is also the reason why some 3rd party batteries will take a long time to charge an iPhone if they only supply 500 mAH of current. I suspect that this is also why some cases, like the Mophie JuicePack Air, require you to discharge the secondary battery before draining the main iPhone battery for maximum charging use, since most batteries do not maintain power regulation as they discharge and may go out of the regulation specs. (This is of interest to me as an iPod Touch owner, since Mophie just came out with a JuicePack Air for the iPod Touch -- however, it appears to disable the internal speaker whether or not the earbuds are plugged in when the iPod is in the case, and also appears to disable use of the volume, start/stop, and voice control functions of the headset earbuds that com with the iPod Touch 3GS if they are used while the device is in the Mophie JuicePack Air case. This is based on user comments for this product at the Apple Online Store.) Incidentally, the 10 W Power Adapter for the iPad will
Re: Charging devices from Computer USB ports Additional comments on iPhone and iPad charging [was Re: A USB device is drawing too much power]
Hi Esther, Thank you. I'll try this. Resetting the PRAM has been tried before, but I'm supposing holding down the power button when battery is removed is some sort of cycle? I'll add it to resetting the PRAM again and let you know how it works out. Regards, Nic Mobile Me: nic2...@me.com Skype: Kvalme MSN Messenger: nico...@home3.gvdnet.dk AIM: cincinster yahoo Messenger: cin368 Facebook Profile My Twitter On May 7, 2010, at 2:18 AM, Esther wrote: Hi Nic, I'll cc this to the viphone list, since the last part of this post is about USB power usage and charging for the iPhone, iPod Touch and iPad. I'm not sure I qualify with respect to knowing a lot about hardware, USB devices, and electricity, but I'll try to answer your question, although I've never had OS X shut a device down with a message that it was drawing too much power. However, I did just make a recent trip where I had to troubleshoot one of the USB ports of a MacBook. Devices that were plugged into that port didn't work properly: printer cables wouldn't relay signals to the attached peripheral, iPods would not be recognized by iTunes, and a plugged in mouse was evidently powered (lit up), but not enough to register clicks on the machine. All these devices worked correctly when plugged into the other USB port. Power cycling with restart and repairing permissions didn't help. (I only tried the permissions repair because the Software Update had just been run to install a security update before the problem behavior.) What did work was resetting the PRAM, which apparently restored the USB port to its full power. If the source of your problem is not the aging of your headphones but the USB current support from your computer, this fix might help. I'll give you the instructions I received from Apple's Tech Support, since they're slightly different from what is in the Knowledge Base article. 1. Power down the computer and remove the battery from the MacBook. (On my model you need to get a thick coin, like a U.S. nickel, to insert in the slot of the lock for the battery, and give it a quarter turn clockwise to rotate it into the unlock position so the side of the battery near the lock will pop up, and so that the battery can be removed.) 2. With the battery removed, hold down the power button for at least 12 seconds. 3. Replace the battery. (On my model, you insert the side near the left edge of the laptop so that it engages, and then swing the other end so that it slots into the lock position. Then you use the coin to turn the slotted lock a quarter turn counter-clockwise to lock again.) 4. Hold down the Command, Option, P, and R keys while you power on your laptop. I press down the Command, Option, and R keys with my left hand (little finger on the Option key, ring finger on the Command key, and either middle or index finger on the R key). I press the thumb of my right hand on the P key and push down on the power button with the middle finger of my right hand. 5. You need to keep the Command, Option, P, and R keys pressed for at least 3 start-up chimes before releasing them in order to reset the PRAM. 6. Log in as usual and check your USB port connections. This fixed all the problems with the USB ports. I think, because the mouse was being powered, but not enough to register clicks with the system, that full power wasn't going to one of the USB ports. I'll point you to the Apple Knowledge Base article on Apple Computers: Powering a peripheral through USB: http://support.apple.com/kb/HT4049 Computer USB 2 ports are supposed to be rated for 500 mAH. That's less than the 1000 mAH you'll get from an AC outlet (in the U.S.) with a USB charger for the iPhone or iPod Touch, which is why charging your device on the computer's USB port is slower, and which is also why the earlier iPods and iPhones could charge from FireWire connectors that didn't have the same limitation. Apple shifted the standard connector for its iPods and iPhones to USB2 because most Windows computers didn't have FireWire (a.k.a. IEEE 1394) ports. This is the source of some of the battery charging error messages that are seen with some iPhone cases -- all devices are now supposed to use chargers that adhere to the more limited current capacities for the USB2 standard. This is also the reason why some 3rd party batteries will take a long time to charge an iPhone if they only supply 500 mAH of current. I suspect that this is also why some cases, like the Mophie JuicePack Air, require you to discharge the secondary battery before draining the main iPhone battery for maximum charging use, since most batteries do not maintain power regulation as they discharge and may go out of the regulation specs. (This is of interest to me as an iPod Touch owner, since Mophie just came out with a JuicePack Air for the iPod Touch -- however, it appears to disable
Re: Charging devices from Computer USB ports Additional comments on iPhone and iPad charging [was Re: A USB device is drawing too much power]
Hi Nic, I've never used resetting the PRAM to fix a USB port issue before on a Mac -- only used it for audio sound repairs. However, the part about removing a battery and holding down the power button with the battery out (to discharge the capacitor) is something I've had to do before with an IBM ThinkPad laptop to reset electronic components. So that may work in your case, too. HTH Cheers, Esther Nicolai Svendsen wrote: Hi Esther, Thank you. I'll try this. Resetting the PRAM has been tried before, but I'm supposing holding down the power button when battery is removed is some sort of cycle? I'll add it to resetting the PRAM again and let you know how it works out. Regards, Nic Mobile Me: nic2...@me.com Skype: Kvalme MSN Messenger: nico...@home3.gvdnet.dk AIM: cincinster yahoo Messenger: cin368 Facebook Profile My Twitter On May 7, 2010, at 2:18 AM, Esther wrote: Hi Nic, I'll cc this to the viphone list, since the last part of this post is about USB power usage and charging for the iPhone, iPod Touch and iPad. I'm not sure I qualify with respect to knowing a lot about hardware, USB devices, and electricity, but I'll try to answer your question, although I've never had OS X shut a device down with a message that it was drawing too much power. However, I did just make a recent trip where I had to troubleshoot one of the USB ports of a MacBook. Devices that were plugged into that port didn't work properly: printer cables wouldn't relay signals to the attached peripheral, iPods would not be recognized by iTunes, and a plugged in mouse was evidently powered (lit up), but not enough to register clicks on the machine. All these devices worked correctly when plugged into the other USB port. Power cycling with restart and repairing permissions didn't help. (I only tried the permissions repair because the Software Update had just been run to install a security update before the problem behavior.) What did work was resetting the PRAM, which apparently restored the USB port to its full power. If the source of your problem is not the aging of your headphones but the USB current support from your computer, this fix might help. I'll give you the instructions I received from Apple's Tech Support, since they're slightly different from what is in the Knowledge Base article. 1. Power down the computer and remove the battery from the MacBook. (On my model you need to get a thick coin, like a U.S. nickel, to insert in the slot of the lock for the battery, and give it a quarter turn clockwise to rotate it into the unlock position so the side of the battery near the lock will pop up, and so that the battery can be removed.) 2. With the battery removed, hold down the power button for at least 12 seconds. 3. Replace the battery. (On my model, you insert the side near the left edge of the laptop so that it engages, and then swing the other end so that it slots into the lock position. Then you use the coin to turn the slotted lock a quarter turn counter-clockwise to lock again.) 4. Hold down the Command, Option, P, and R keys while you power on your laptop. I press down the Command, Option, and R keys with my left hand (little finger on the Option key, ring finger on the Command key, and either middle or index finger on the R key). I press the thumb of my right hand on the P key and push down on the power button with the middle finger of my right hand. 5. You need to keep the Command, Option, P, and R keys pressed for at least 3 start-up chimes before releasing them in order to reset the PRAM. 6. Log in as usual and check your USB port connections. This fixed all the problems with the USB ports. I think, because the mouse was being powered, but not enough to register clicks with the system, that full power wasn't going to one of the USB ports. I'll point you to the Apple Knowledge Base article on Apple Computers: Powering a peripheral through USB: http://support.apple.com/kb/HT4049 Computer USB 2 ports are supposed to be rated for 500 mAH. That's less than the 1000 mAH you'll get from an AC outlet (in the U.S.) with a USB charger for the iPhone or iPod Touch, which is why charging your device on the computer's USB port is slower, and which is also why the earlier iPods and iPhones could charge from FireWire connectors that didn't have the same limitation. Apple shifted the standard connector for its iPods and iPhones to USB2 because most Windows computers didn't have FireWire (a.k.a. IEEE 1394) ports. This is the source of some of the battery charging error messages that are seen with some iPhone cases -- all devices are now supposed to use chargers that adhere to the more limited current capacities for the USB2 standard. This is also the reason why some 3rd party batteries will take a long time to charge an iPhone if they only supply 500 mAH of current. I suspect
