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Usb charge

OP WarlockM

21st November 2010, 03:22 PM   |  #11  
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My device with no load it have 5.21v and with load 5.03v so it's not from him and i have another supply 5v/12 amp and it's doing the same (not charging, only with data shorted).
When u r trying to measure the original ps u can read ~7k between gnd and data but from 5v to data u cant because it have some capacitors.
Maybe samsund did something else, i have to try, maybe data pins drawing some current (mA) and that's why it's not working with only shorting them.
For the moment it's the only (working) solution i've found and i'm happy with it .

P.S. If i'm not finding anything else the last resort will be to open the original ps

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22nd November 2010, 04:12 PM   |  #12  
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USB Charger
This is what worked for me.

Items Needed:

USB Extension Cable
33k-Ohm Resistor (Shack Part No. 271-1129)
10k-Ohm Resistor (Shack Part No. 271-006)

Steps:

1. Cut USB Extension Cable in half, lets name the 2 halves, the half you will plug into the power suppy will be called "Cable A" and the half that you plug into the Galaxy Tab Data Cable will be called "Cable B"

2. On 'Cable A" strip outer plastic to expose all wires within, eliminate Green and White on this cable only as it will not be needed, leaving you with only the Red and the Black Cables

3. On "Cable B" strip outer plastic to expose all wires within, this should leave you exposing all 4 wires

4. On "Cable B" strip both the Green and White wires and join thes 2 wires with the 2 resistor ends (you should be using the resistor ends that have the red band with these wires), these can be joined by either soldering or just twisting together.

5. Strip Red wire from both cables and join together with the 33k-Ohm Resister (this will be the larger of the 2 resistors and should also be the end with the Gold Band) and as well join these together with solder or just twisting together.

6. Repeat the above process with the Black wires and 10K-Ohm Resistor.

7. No finally use Electrical Tape or Shrink Tubing to cover all your work.

This worked using it on a Champtek 5v 2.1a USB Car Charger and Home Charger. Also worked with iPhone charger. Also works with Original Galaxy Tab.

Hope this helps out.
Last edited by rick75204; 22nd November 2010 at 04:16 PM.
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6th December 2010, 10:22 AM   |  #13  
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May I just ask some clarifying questions?

Quote:
Originally Posted by rick75204

This is what worked for me.

...

4. On "Cable B" strip both the Green and White wires and join thes 2 wires with the 2 resistor ends (you should be using the resistor ends that have the red band with these wires), these can be joined by either soldering or just twisting together.

Does it matter WHICH resistor you join to which of these two wires?

Quote:
Originally Posted by rick75204

5. Strip Red wire from both cables and join together with the 33k-Ohm Resister (this will be the larger of the 2 resistors and should also be the end with the Gold Band) and as well join these together with solder or just twisting together.

So that you have effectively bridged the red wire with 30K-Ohms to one of either green or white running to the TAB?

Quote:
Originally Posted by rick75204

6. Repeat the above process with the Black wires and 10K-Ohm Resistor.

And bridged the black wire with 10K-Ohms to the other of either green or white running to the TAB?

Would this be an accurate picture, with the 33K Ohm Resistor on the left, and the 10K Ohm Resistor on the right?
6th December 2010, 12:08 PM   |  #14  
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I think the intention was that you short the green and white wires together: so you are connecting both wires to both resistors.

That way the two data lines are both held at a fixed voltage of about 1.2V
7th December 2010, 04:39 PM   |  #15  
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Thanks, that clarified it.
7th December 2010, 07:44 PM   |  #16  
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I noticed today that if I connect my Tab to my keyboard (standard Apple USB KB with keypad, connected to a circa 2006 iMac), the device started charging according to battery stats. When it was plugged in it was at 48% and it ended up at around 60% after a few hours. Am I being deceived or something? I was under the impression that it would only charge if connected to the mains charger. Well I guess I'll see how long it runs now it's off the leash and see if it lasts till the morning (left my charging cable at work - D'oh!).
8th December 2010, 09:45 AM   |  #17  
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No, it definitely does charge even when it says it isn't - just slowly. I've got a 2A non-official USB charger that charges it up pretty quick, but still says it isn't charging. If the screen is off, it will even charge off one of those tiny Kindle chargers that must be delivering less than 500mA, but *really* slowly.
13th December 2010, 03:15 PM   |  #18  
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Question Clarify
Sorry guys, only a clarification.

As far as i understood:
  1. the GT DOES charge with *any* charger (or connection to PC);
  2. if you use the original charger (2Amp), it charges showing the charging-icon;
  3. if you use a non-original charger, it charges in any case but NOT showing the charging-icon and depending on the charger power (even 1Amp charges, or 500mAmp, *VERY-REALLY* slowly);
  4. if you use a non-original charger with the two resistors (33k + 10k) it charges showing the icon (even with a 1Amp).

Can anybody confirm if i understood well?

Thanks!!
13th December 2010, 03:37 PM   |  #19  
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Quote:
Originally Posted by eiem

Sorry guys, only a clarification.

As far as i understood:

  1. the GT DOES charge with *any* charger (or connection to PC); Yes but slower than the original charger
  2. if you use the original charger (2Amp), it charges showing the charging-icon; Yes, exactly
  3. if you use a non-original charger, it charges in any case but NOT showing the charging-icon and depending on the charger power (even 1Amp charges, or 500mAmp, *VERY-REALLY* slowly); Yes.
  4. if you use a non-original charger with the two resistors (33k + 10k) it charges showing the icon (even with a 1Amp). Depends, i get various results even though i am using the mod since day 1.

Can anybody confirm if i understood well?

Thanks!!


Thats it for now.
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15th December 2010, 12:59 AM   |  #20  
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It seems that the Tab could recognize the status of the usb connection by measuring the usb data rx/tx wire level. If it is not shorted, the "pluged in but not in charging" status will appear, as the mismatch voltage of the usb connection is made.

Sent from my XT701 using XDA App

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