Author Topic: Reverse polarity (Read 208 times)

Erwin Ried · « **on:** August 14, 2024, 09:21:14 am »

Hi! by mistake a negative-center 12V plug was connected to this archer tp-link mr600(EU) 4g router, this is the damage:

I imagine there was a fuse and some regulator? by any chance anyone has a hint how to make it work again? there is - + 12V to the right side of the switch button (the bigger pads, T13 is positive)

squadchannel · « **Reply #1 on:** August 14, 2024, 09:40:52 am »

When a regulator is damaged, most of the time the input voltage is output on the output side.
You would first try applying voltage to the output side of the regulator. If it works fine, then I would replace to common regulator such as the 780x.
The voltage can be guessed by examining the datasheet of the chip or other device that is supplying the voltage.

Erwin Ried · « **Reply #2 on:** August 14, 2024, 10:44:51 am »

you think those fbxx components where regulators? I was gonna to do something like that but I think they are so small, because the whole router has heatsinks and such, so I wonder how could that small regulator be the only one.

Could it be a step down 12->5V for example to be later turn into 3 o 1.8V ? it is weird that just by the power input there is not inductors either, those are very far away with some "power-handling-looking" circuitry

squadchannel · « **Reply #3 on:** August 14, 2024, 10:54:29 am »

FB is probably a ferrite bead.

want to make it work for now, supply power to C348, 349, and 350, taking care of the polarity. advisable to test while limiting the current.

I wondered had a regulator, but there doesn't seem to be one. Perhaps there is a regulator elsewhere not shown in the image.