I usually carry a PowerCore 5000 powerbank with an attached USB-A to USB-C cable in my purse. In hindsight, always having the cable attached to it (rather than just when using it) is not the best idea, as it exercises quite some leverage forces on the USB port. So, to little surprise, at some point the output port stopped working unless the cable connected to it was pressed into the right direction.

Luckily, the powerbank is quite easy to open up, repair, and re-assemble.

Caution: This powerbank contains a 18.5 Wh LiIon cell. In normal operation, the (dis)charge PCB is in charge of battery management tasks like short circuit protection. Disassembly exposes the raw 26650 LiIon cell, which likely does not contain a built-in protection circuit. Puncturing, shorting, heating, or otherwise mishandling it can lead to fire and/or explosion. Don't disassemble a powerbank unless you know what you are doing. Don't work with soldering irons close to LiIon cells unless you really know what you are doing.

Teardown

The connector side of the power bank features a glued-on plastic cover on top of a screwed-on plastic cover.

The glued-on cover can be pried open with moderate effort by placing a suitable object between the two plastic covers, revealing the screwed-on second plastic cover.

With the powerbank placed on a table (not held in your hands), you can now take a PH00 screwdriver to release the three screws that hold it in place. Once that is done, simply lift the case up, revealing the actual circuitry (LiIon cell and PCB). If you were holding the powerbank in your hands while removing the screws, the circuitry likely fell out instead.

The innards are quite simple: A single 26650 LiIon cell; a single PCB; and a two-part plastic assembly featuring a button and LED diffusors.

Repair

In my case, the culprit was a loose solder connection between the USB-A output port and the PCB. Nudging the capacitor out of the way and carefully applying some additional solder to its GND and VCC pins solved the issue. Just be wary of the fact that you're operating a soldering iron next to a LiIon cell that does not like triple-digit temperatures…

Re-Assembly

• Slide the button assembly and diffusor back into the case until it locks into place.
• Slide the LiIon cell and PCB assembly back into the case.
• Place the powerbank on its bottom (i.e., so that the USB ports face up).
• Place the plastic cover on top of the PCB assembly and tighten its three screws.
• Put the glued-on top cover back on. It comes with alignment pins; in my case I did not have to apply new glue.