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My uncle asked me to repair a tablet but when I opened the tablet I saw that the micro USB connector was completly ripped off the board and I lack the tools to scrape free some of the copper to solder a new connector to it because the trace is just so tiny.

I noticed some pads on the other side of the board which are likely for the connector.

My 3 questions are:

  1. Can I solder the connector with some wires to the test pads to charge the tablet?
  2. How do I identify V+, V-, D+ and D-? I couldn't find any hints on the board. The board sticker says LELA24CF4JD04M2, but I couldn't find any schematics with Google.
  3. The tablet has some more pads for an optional docking station (unfortunately no longer for sale.) I can imagine that the tablet can also be charged via some of those pads. Again: How would I go about identifying which pads I could hijack and solder to my new micro USB connector?

test pads?

board

Dock connector

Edit: As per request her,e is the other side of the board. The tablet model is TCL 8088x or also know as Alcatel 3T 10" LTE.

enter image description here

Edit2: The pins I have identified so far:

enter image description here

The connector I am trying to install:

enter image description here

I have identified the GND and V+ pads. As the original traces are broken, I thought about replacing the micro USB with a USB-C connector while I am at it. I have added the connector I am using to my original post. I have soldered b12 and b9 to the pins which I have also marked in my original post. The battery does in fact charge but only with 100mA. If I understood correctly, USB-C only pulls more if CC1 and CC2 are bridged with a resistor. USB-C connectors with less than 8 pins should have CC1 and CC2 connected by default internally. Is it mandatory to connect d+/- also to pull more current?

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    \$\begingroup\$ You need to show us the other side of the board, the side with the ripped pads. \$\endgroup\$ Commented Feb 24 at 17:16
  • \$\begingroup\$ What is the make and model of the tablet? \$\endgroup\$ Commented Feb 24 at 18:32
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    \$\begingroup\$ "I lack the tools to scrape free some of the copper" - don't do it until you've had more information, but the tip of a surgical scalpel (a few dollars) wielded gently will do that. Practise on some other trace before doing it for real. \$\endgroup\$ Commented Feb 24 at 18:47
  • \$\begingroup\$ @AndrewMorton I scraped the trace using a scalpel befor but the traces are so thin neither the solder nor the wire wanted to Stick to the trace. I also tried to solder some wire right before the cap but while they seem rather big on the picture they are microscopic irl. \$\endgroup\$
    – Olaf Olaf
    Commented Feb 25 at 2:28

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Thank you for the additional picture, which allows us to see that:

Yes, you can wire a new USB connector to those test pads.

Use a meter in the Continuity mode to find out which pad is for which contact in the USB connector.

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    \$\begingroup\$ I have identified the GND and V+ pads. As the original traces are broken i thought about replacing the micro usb with a usb c connector while i am at it. I have added the connector i am using to my original post. I have soldered b12 and b9 to the pins which i have also marked in my original post. The battery does infact charge but only with 100mah. If i understood correctly usb-c only pulls more if CC1 and CC2 are bridged with a resistor. USB-C connectors with less than 8 pins should have CC1 and CC2 connected by default internally. Is it mandatory to connect d+/- also to pull more amps? \$\endgroup\$
    – Olaf Olaf
    Commented Mar 7 at 11:23
  • \$\begingroup\$ "Is it mandatory to connect d+/- also to pull more amps? " - I suggest you start a new post and ask that question. \$\endgroup\$ Commented Mar 7 at 13:20

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