Zigbee Socket Z2 ZHU2114 Range Issue After Year of Operation

Good afternoon,

After more than a year of operation, the socket has lost its Zigbee range. Originally 5-8m to the gateway was not a problem, and suddenly the max is 35-40cm. It has worked so far at about 3m. Apart from the loss of range functionally everything works ok. Overvoltage, lightning etc is rather out of the question. Pairing , control correctly.
So I rather suspected the RF track, matching circuit or cable and antenna. I soldered components, checked inductance and changed capacitances. No effect. I cannot find the datasheet of the microcontroller. The RF output has two pins connected by inductance. From one end the capacitance to ground, and from the other end (and the uC pin) further to the boost-filter circuit and to the antenna. The circuit holds the voltages stably. A faulty RF power amplifier in the Zigbee SOC, an out of tune resonator?
Maybe someone can help with experience, a note, or a similar case.
Power and voltage measurement circuit : BL0940
Zigbee microcontroller : Z2 ZHU2114
Surprisingly a pretty decent design. The solder and pcb look nice, and it cost about 25zl at majfriend.
Attached Z2 ZHU2114 in another device, but the RF part looks similar to mine (pic2). Zdj3 ,4 my device

You have attached a photo of the green plate with the battery space - what is that?

freebsd wrote:

You've included a photo of the green board with the battery space - what is it?

probably a door open sensor , zigbee. But as I wrote clearly in the text this is not my device. Just an overview of the same soc and RF block

>>20856432
Hi!
Have you been able to solve the problem? My socket exhibits these characteristics with a tendency to under-range. At first it worked without any problem on the ground floor where the coordinator was upstairs, then only within the boundaries of the room, and after consecutive days I have to put the coordinator on the socket to pair it. When moved to another location it loses connectivity. Maybe some antenna has become disconnected? I don't know what it looks like inside.

Greetings
.

Colleagues I have an identical problem with range fading - have you perhaps figured out the subject?

>>21265009 I have looked carefully at the RF path. Coil capacitances, resistors are ok . It works at a distance of about 10cm from the gate antenna. I did not want to connect under oscilloscope. Imo the RF termination stage in the SOC is failing. Check if it works close to the gate, without pairing again if it has been paired so far. The circuit looks solid but maybe the SOCs were faulty or the RF RLC miscounted and died. I'm wasting my time on this, I made an accurate 3 phase energy meter under DIN rail on ADE7759 and ESP32s3