We bring back the “brikted” devices

Upd: only today I noticed that for some reason he himself had transferred the review to drafts. Apparently, the hand trembled; correcting.
Many of us have the sad experience of “turning intobrick "routers, WiFi-points, printers and other similar garbage. I just started updating the firmware, the light in the house blinked - and the expensive device seems to be turned on, but does not react to anything.

In some cases, there is still a chance for resurrection.
The fact is that some good manufacturersplaced in the device contacts of the COM port. If you connect to it during the launch of the unit, then you can “talk” with the bootloader firmware and upload the correct firmware file to the place of the damaged firmware.
Here, for example, an article on Habré, which describes how much more advanced firmware from a similar Zyxel model is slipped into such a reception by the D-Link router: habrahabr.ru/post/123699/
In my case, recovery required chinese ip camera. The procedure for upgrading the firmware from the factory version to the latest stable required five iterations and at the last I stumbled, slipping it throughThe web interface is not that file. The camera worked after that, but it was unstable, but it was impossible to roll back to another firmware - all attempts ended in hangs. After searching the Internet, it was found description of the recovery procedure, for this it was necessary to unscrew the camera and connect to the "service" connector on the board.
Since now laptops are all around, oldThere was no good COM port anywhere; I had to take an adapter from USB. It was important that the majority of adapters on sale work on a USB voltage of 5 volts, and a significant part of the electronics functions with 3V. If you connect to such a device with 5V, you can finally finish the repaired device. That is why I took such an adapter, and not one of the many ready-made USB-COM cables on Ali.
The required adapter was found on Ali. He arrived in 40 days, in a simple envelope, but in five layers of "pimple". Included was a set of mother-mother jumper wires:

The seller did not have links to the driver, but Yandex turned out to be a matter of two minutes - www.silabs.com/products/mcu/Pages/USBtoUARTBridgeVCPDrivers.aspx (works under Windows 7 64bit).
The adapter uses a virtual COM port (in mycase is COM 44). The speed in the settings of the driver is already indicated suitable - 9600bps. You can connect to the port via “PuTTY” and fill in anything you like.