I posted about this in the Debian on Pinephone board a little while back, since I use Mobian, looking for a vibration mtor test command but since it's more of a hardware issue maybe someone else will know something about it...
Back when I replaced my cracked screen I managed to damage the vibration motor on the USB-C side board by prying it up in the wrong place and breaking it apart.
I recently bought a replacement USB board with vibrator and installed it but still am not getting the confirming vibration when turning the phone on etc. Is there a command or program in any of the Pinephone distributions that can be used to manually test the vibration motor to see if it can work at all? (Charging is working through the USB port so I know the board is connected.)
Sorry for bringing this old thread back up, but since I've had similar problems recently I thought it might help someone finding this info:
I also replaced my USB-C side board recently and everything worked fine afterwards. But a while later the vibration motor stopped working out of the blue. I didn't care about it much and had no time to look into it, but now I finally got around to it and found the problem.
First I thought the motor itself was broken. To confirm this, I applied some low voltage to the connections of the motor (with a breadboard power supply, some resistors and wires). Since the part is unknown and there is no data sheet on it, I started low, but later I saw in the schematics that it should take 3.3 V. Applying 1.1 V had no effect, but with 2.2 V the motor was buzzing, so that was not the problem.
Then I checked the connections through the flex cable that connects the motor to the side board for continuity with a multimeter (solder joints of the motor to solder joints on the board). A broken flex cable is what caused me to replace the board in the first place, it's quite fragile when removing the board. No problem there either, though I could only reach a very small bare metal surface on top of the cable which I don't believe was the actual solder joint (the cable has a plastic coating, so the joint is rather underneath).
Last I checked continuity from the solder joints of the motor to the pins on the connector of the USB-C board where you connect the cable to the mainboard. The corresponding pins should be on the top row of the connector towards the middle (pins 10 & 11; I just swept along all of them to check for a signal). And that's where the problem was, no continuity here. Since the connection through the flex cable was fine, the problem must have been in between the connection of the flex cable (speaker & motor) and the connector towards the mainboard. Some connection inside the board suddenly failing seemed unlikely, so I figured it's probably the solder joint where the flex cable (with the motor on the other end) connects to the PCB. I used hot air (310 C) and some careful pressure with tweezers on the joints (careful not to slide the cable around once the solder melted, only press it down) for a couple of seconds in the hope of reworking the joints towards the better. After 2 or 3 tries I did have continuity again and vibration now works again.
So in the end it wasn't too hard of a fix if you have the tools. A soldering iron might work as well for heating the joints (probably best with a flat tip), but I haven't tried (only with a very pointy tip, but that didn't work).
