Suddenly WiFi signal strength is poor
08-21-2021, 08:27 AM
I was running the latest Mobian with 5.10 Kernel. I tried a range of different software first (Postmarket Plasma, Postmarket Phosh, a few distros on the the multi-boot SD card). I tried upgrading to the 5.13 kernel on Mobian and that also didn't make a difference to the signal strength.
I've taken the phone apart a few times at this point trying to understand what could have broken. I am assuming the small shield on the upper right corner on the back of the mainboard is the RTL8723CS. (I didn't see any other place it could have been). That shield is right next to the antenna pins and the traces disappear in the PCB. If there is a problem with the mainboard it doesn't look like there's anything I could do about it. I don't think it can be a loose connection either if the case antenna just presses against the pins when you screw it down.
Running the phone without the back frame I get the same signal strength (so the antenna isn't being useful), but that doesn't really help me narrow down the problem. I tried effecting the signal strength by attaching other wireless antennas, pieces of wire, or just my finger. I didn't see much change, but I'm not sure that's a valid test.
I did try those commands to change the transmit power but I couldn't get by "Operating not Permitted". I couldn't tell if it was because the driver doesn't support that, or if it's my regulatory environment. Even passing it iwconfig wlan0 txpower off failed with that error.
At this point I don't know any other tactic then to buy a back frame and a mainboard and see which part fixes the problem.
I've taken the phone apart a few times at this point trying to understand what could have broken. I am assuming the small shield on the upper right corner on the back of the mainboard is the RTL8723CS. (I didn't see any other place it could have been). That shield is right next to the antenna pins and the traces disappear in the PCB. If there is a problem with the mainboard it doesn't look like there's anything I could do about it. I don't think it can be a loose connection either if the case antenna just presses against the pins when you screw it down.
Running the phone without the back frame I get the same signal strength (so the antenna isn't being useful), but that doesn't really help me narrow down the problem. I tried effecting the signal strength by attaching other wireless antennas, pieces of wire, or just my finger. I didn't see much change, but I'm not sure that's a valid test.
I did try those commands to change the transmit power but I couldn't get by "Operating not Permitted". I couldn't tell if it was because the driver doesn't support that, or if it's my regulatory environment. Even passing it iwconfig wlan0 txpower off failed with that error.
At this point I don't know any other tactic then to buy a back frame and a mainboard and see which part fixes the problem.