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enter image description hereI have attempted to replace a micro USB connector on a PCB. It is used to charge the battery of the device. Once it was in place and I connected the charging cable I measured the voltage on pin 1 (probe on ground and probe on pin 1), I got nothing.

I then desoldered the connector and measured again with the charging cable plugged in, and there was 5 V on pin 1 on the connector.

What can cause the voltage on pin 1 to disappear once the connector is on the board? I had my probe on the actual pin of the connector, not on the trace. The pins were not bridged.

I've included a pic. It's a little blobby but the pins aren't bridged.

Additional:

The original connector was badly damaged. I think I may need a different connector with reversed polarity.

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    \$\begingroup\$ Sounds like you shorted the pin to ground while soldering. Perhaps a solder bridge to a mounting pad? \$\endgroup\$
    – Hearth
    Commented Sep 2, 2022 at 20:51
  • \$\begingroup\$ Sorry, I just did a ninja edit. No solder bridge. I didn't measure a short either. \$\endgroup\$ Commented Sep 2, 2022 at 20:52
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    \$\begingroup\$ Need more info, a pic would be nice. Sometimes flux can leave oxides that are hard to probe \$\endgroup\$
    – Voltage Spike
    Commented Sep 2, 2022 at 20:56
  • \$\begingroup\$ Thank you both. I will add pic as soon as I can. \$\endgroup\$ Commented Sep 2, 2022 at 21:00
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    \$\begingroup\$ Can you do a continuity test on the power leads ? (off power of course). Also the 2 passives below the connector look burned no ? \$\endgroup\$
    – Rahmany
    Commented Sep 3, 2022 at 9:18

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Thank you all.

I believe it will not be worth the trouble getting a new connector. I've tested the board today and I'm getting a short to ground on the connector and the two components right below the pins seem dead as well. Lesson to me not to assume anything and double check.

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