Forums

Phone Charging

Started by rickman November 19, 2017
A friend has an old Motorolla W376g phone and the charger can't be found.  I 
can get it to charge from a car charger I use as well as from a desktop 
multi-outlet charger I have.  But a couple of different wall wart chargers 
won't charge it while they will charge any of my devices.  I did a search 
and can't find any details on why this might not work other than that 
Motorola warns to only use Motorola chargers of course.

I've read that some phones or chargers have a resistor indicating the 
charging capacity, but I don't recall which end has the resistor.  Also, I 
think this is not done for the lower current devices, rather for the high 
current devices.  I'm wondering if the phone is looking for this resistor. 
Obviously I'll need to pay for a charger that clearly says it will charge 
this phone.  I just don't get what is happening in this case.

Any ideas?

-- 

Rick C

Viewed the eclipse at Wintercrest Farms,
on the centerline of totality since 1998
On Sun, 19 Nov 2017 17:27:10 -0500, rickman <gnuarm@gmail.com> wrote:

>A friend has an old Motorolla W376g phone and the charger can't be found. I >can get it to charge from a car charger I use as well as from a desktop >multi-outlet charger I have. But a couple of different wall wart chargers >won't charge it while they will charge any of my devices. I did a search >and can't find any details on why this might not work other than that >Motorola warns to only use Motorola chargers of course. > >I've read that some phones or chargers have a resistor indicating the >charging capacity, but I don't recall which end has the resistor. Also, I >think this is not done for the lower current devices, rather for the high >current devices. I'm wondering if the phone is looking for this resistor. >Obviously I'll need to pay for a charger that clearly says it will charge >this phone. I just don't get what is happening in this case. > >Any ideas?
I think they put a 1k ressitor from the USB+ to D+ so the phone knows its a wall wart, other wise the usb protocol takes care of requesting power from the hub. My Old Razr is setup this way. Cheers
On Sun, 19 Nov 2017 17:27:10 -0500, rickman <gnuarm@gmail.com> wrote:

>A friend has an old Motorolla W376g phone and the charger can't be found.
Mini USB connector. You'll need to add a 200k resistor and short pins 2 and 4: <http://pinoutguide.com/ChargersAdapters/razrv3_charger_pinout.shtml> -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
Jeff Liebermann wrote on 11/19/2017 8:02 PM:
> On Sun, 19 Nov 2017 17:27:10 -0500, rickman <gnuarm@gmail.com> wrote: > >> A friend has an old Motorolla W376g phone and the charger can't be found. > > Mini USB connector. You'll need to add a 200k resistor and short pins > 2 and 4: > <http://pinoutguide.com/ChargersAdapters/razrv3_charger_pinout.shtml>
I just realized this connector resistor issue is not likely to be my problem... I think. I can charge this phone using two generic adapters I have. One is a box with six high current outputs, at least two rated for 2.1 amps and the other four rated for 1 amp or maybe 4 and 2 (other way around). The other unit that will work with the phone is a car charger, but then that one is also a high current charger. They are all connected with the same cable and I'm pretty sure the charger end of the cable only has four pins so there is no place to connect the resistor to the "ID" pin. This phone won't charge from my laptop, so I don't think the phone is negotiating anything over the USB data pins, or maybe it is? I don't think either of the chargers have a USB host built in and the laptop clearly does. I'm still stumped. -- Rick C Viewed the eclipse at Wintercrest Farms, on the centerline of totality since 1998
In sci.electronics.repair rickman <gnuarm@gmail.com> wrote:

> I'm still stumped.
Because you aren't listening to the other responses, those phones need a modified cable to charge. Many of those type also used that mini (micro?) usb jack to use as headphones, standard cable to export the photos and of course to charge it. Anyway, I doubt your "I can't find it" claim... https://www.amazon.com/Motorola-W376g-Phone-Standard-Charger/dp/B00KC6CW2G seems to be what you need. -bruce bje@ripco.com
Bruce Esquibel wrote on 11/20/2017 6:29 AM:
> In sci.electronics.repair rickman <gnuarm@gmail.com> wrote: > >> I'm still stumped. > > Because you aren't listening to the other responses, those phones need a > modified cable to charge. Many of those type also used that mini (micro?) > usb jack to use as headphones, standard cable to export the photos and of > course to charge it.
I have no idea what you read. Of course I have a cable with the mini USB connector. There's no way to plug it in otherwise. I don't know why anyone would bother to tell me that. I said I could charge the phone with two chargers I have using the same cable as used with the two chargers that won't charge the phone. So clearly the cable is not the issue. Further it is clear the chargers don't have the resistor because in the Motorola cable it is on a pin that does not exist in the type A connector on the chargers, so no way to connect it. I said all this in the post you replied to. I think you didn't listen to my post.
> Anyway, I doubt your "I can't find it" claim... > > https://www.amazon.com/Motorola-W376g-Phone-Standard-Charger/dp/B00KC6CW2G > > seems to be what you need.
"can't be found" is referring to the charger that came with the phone. That is why I am looking for another way to charge this phone. The original charger is MIA. Thanks for your help. I've measured the voltage on the different chargers, but didn't write down the numbers as they were all pretty close to 5 volts. One web page did mention the phone would not charge if the voltage was too high or too low. I'm wondering how critical the high voltage is. Or possibly the phone is triggering to not charge because the low voltage is too low and I don't see it on the USB meter because it is too quick to see with the slow update rate? The chargers that work are definitely higher current. -- Rick C Viewed the eclipse at Wintercrest Farms, on the centerline of totality since 1998
These are handy devices to measure the working capacity of the charger: 
https://www.ebay.com/sch/sis.html?_nkw=Practical+USB+Charger+Current+Voltage+Detector+Battery+Tester+Volt+Meter+Ammeter&_id=321912291635&&_trksid=p2060353.m2749.l2658

The cheapest ones have worked fine for me.




On 11/20/2017 4:26 AM, rickman wrote:
> Bruce Esquibel wrote on 11/20/2017 6:29 AM: >> In sci.electronics.repair rickman <gnuarm@gmail.com> wrote: >> >>> I'm still stumped. >> >> Because you aren't listening to the other responses, those phones need a >> modified cable to charge. Many of those type also used that mini (micro?) >> usb jack to use as headphones, standard cable to export the photos and of >> course to charge it. > > I have no idea what you read.&nbsp; Of course I have a cable with the mini > USB connector.&nbsp; There's no way to plug it in otherwise.&nbsp; I don't know > why anyone would bother to tell me that.&nbsp; I said I could charge the > phone with two chargers I have using the same cable as used with the two > chargers that won't charge the phone.&nbsp; So clearly the cable is not the > issue.&nbsp; Further it is clear the chargers don't have the resistor because > in the Motorola cable it is on a pin that does not exist in the type A > connector on the chargers, so no way to connect it.&nbsp; I said all this in > the post you replied to.&nbsp; I think you didn't listen to my post. > > >> Anyway, I doubt your "I can't find it" claim... >> >> https://www.amazon.com/Motorola-W376g-Phone-Standard-Charger/dp/B00KC6CW2G >> >> >> seems to be what you need. > > "can't be found" is referring to the charger that came with the phone. > That is why I am looking for another way to charge this phone.&nbsp; The > original charger is MIA. > > Thanks for your help. > > I've measured the voltage on the different chargers, but didn't write > down the numbers as they were all pretty close to 5 volts.&nbsp; One web page > did mention the phone would not charge if the voltage was too high or > too low. I'm wondering how critical the high voltage is.&nbsp; Or possibly > the phone is triggering to not charge because the low voltage is too low > and I don't see it on the USB meter because it is too quick to see with > the slow update rate?&nbsp; The chargers that work are definitely higher > current. >
On Mon, 20 Nov 2017 04:50:57 -1000, John Keiser <johnkeiser@juno.com>
wrote:

>These are handy devices to measure the working capacity of the charger: >https://www.ebay.com/sch/sis.html?_nkw=Practical+USB+Charger+Current+Voltage+Detector+Battery+Tester+Volt+Meter+Ammeter&_id=321912291635&&_trksid=p2060353.m2749.l2658 > >The cheapest ones have worked fine for me.
I have a few of those and use them for testing chargers and phones. Very handy. They're especially fun when I connect them all in series and notice that both the voltage and current readings are not even close to each other. If you're using one for measurements, rather than just fault finding, I suggest you make a calibration chart. I also bought a USB adjustable load: <https://www.ebay.com/itm/282437868849> which is useful for testing if a charger can actually deliver the current printed on the label. Most will not or go into oscillation at the rated current. It's not the best quality instrument, but it works for the purpose intended. -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
On Mon, 20 Nov 2017 17:39:34 +1000, rickman <gnuarm@gmail.com> wrote:

> Jeff Liebermann wrote on 11/19/2017 8:02 PM: >> On Sun, 19 Nov 2017 17:27:10 -0500, rickman <gnuarm@gmail.com> wrote: >> >>> A friend has an old Motorolla W376g phone and the charger can't be >>> found. >> >> Mini USB connector. You'll need to add a 200k resistor and short pins >> 2 and 4: > > I just realized this connector resistor issue is not likely to be my > problem... I think. I can charge this phone using two generic adapters > I have. One is a box with six high current outputs, at least two rated > for 2.1 amps and the other four rated for 1 amp or maybe 4 and 2 (other > way around). The other unit that will work with the phone is a car > charger, but then that one is also a high current charger. They are all > connected with the same cable and I'm pretty sure the charger end of the > cable only has four pins so there is no place to connect the resistor to > the "ID" pin. > > This phone won't charge from my laptop, so I don't think the phone is > negotiating anything over the USB data pins, or maybe it is? I don't > think either of the chargers have a USB host built in and the laptop > clearly does. > > I'm still stumped. >
Some usb leads for chargers only run the +5 and Gnd - so they can't be used on PC's etc -- The latest set of Shadow Broker tools shows the UK, USA, Canada, Australian and New Zealand spy agencies were hacking into domestic home routers. Who gave them permission to spy on our kids?
On Tue, 21 Nov 2017 11:58:18 +1000, "David Eather" <eather@tpg.com.au>
wrote:

>On Mon, 20 Nov 2017 17:39:34 +1000, rickman <gnuarm@gmail.com> wrote: > >> Jeff Liebermann wrote on 11/19/2017 8:02 PM: >>> On Sun, 19 Nov 2017 17:27:10 -0500, rickman <gnuarm@gmail.com> wrote: >>> >>>> A friend has an old Motorolla W376g phone and the charger can't be >>>> found. >>> >>> Mini USB connector. You'll need to add a 200k resistor and short pins >>> 2 and 4: >> >> I just realized this connector resistor issue is not likely to be my >> problem... I think. I can charge this phone using two generic adapters >> I have. One is a box with six high current outputs, at least two rated >> for 2.1 amps and the other four rated for 1 amp or maybe 4 and 2 (other >> way around). The other unit that will work with the phone is a car >> charger, but then that one is also a high current charger. They are all >> connected with the same cable and I'm pretty sure the charger end of the >> cable only has four pins so there is no place to connect the resistor to >> the "ID" pin. >> >> This phone won't charge from my laptop, so I don't think the phone is >> negotiating anything over the USB data pins, or maybe it is? I don't >> think either of the chargers have a USB host built in and the laptop >> clearly does. >> >> I'm still stumped. >> > >Some usb leads for chargers only run the +5 and Gnd - so they can't be >used on PC's etc
They're known as "charging cables", for the obvious reason. "Charging and download", or some such, have all the wires. They're bulkier, less flexible, so there is a reason for both.