SMD Part Identification for Logitech ConferenceCam CC3000e repair

[0xPIT]

Hi,

so, I got this Logitech for free with a mechanical defect that I could repair thanks to PTFE glue that cost 40€.
In course of the repair, I've added a Mini-USB to the camera module to use it stand alone, which worked fine.
Never used the cam at all, but due to current circumstances I fetched the device from the basement to use for remote work, and it no longer works.

Now, there seems to be a power issue. When I plug in the camera, there is high current draw, switching off the base unit.

I look for help to identify the power supply SMD controller with the marking "B3GnSK" – see photo.

Any hints greatly appreciated!
Thanks,

pit

[0xPIT]

Traced the schematics to a DaveCAD...

[benj38]

I am sorry I can't exactly identify the IC, but if you do not mind me asking, are you sure you need to?

I mean, this looks like a simple micro-power buck converter controller with integrated diode(s). The roles of all but one pin in your diagram should be
(clockwise, starting top-left in your diagram): boost, ground, feedback, ? (maybe to set the switching frequency??), input voltage, switching output.
I would simply measure the output voltage without the camera plugged in, and if it falls when you plug it in, try to connect a lab power supply (preferably with current limit capability) as the power source instead of this converter, and see what happens.

Identifying these SMD chips is more luck than anything else, so I usually do that as a last resort, not as the first step.

[fzabkar]

I would also measure the voltage at the feedback pin, if the IC is working correctly. Otherwise measure the feedback resistors and calculate the required feedback voltage for the expected Vout.

[0xPIT]

So, I've removed the IC and it's supporting circuit and bodged one of those 4$ mini buck converter from eb*y --> Works again