Post by: u/Beautiful_Purpose396
Long story short, I have been using my Quest 3 without any issues for a month, didn't drop it and treated it carefully. After a while I started to notice some issues with tracking in passthrough mode. When I tried to rescan my room to setup guardian it failed multiple times and I switched to manual setup. Next day I turned on my Quest 3 and got a black screen with permanent Tracking Lost error. I tried all methods to fix it and nothing helped. After I did a factory reset I'm stuck on the controller pairing screen with no tracking and no ability to connect controllers.
You don't hear about this problem often because Meta is quickly replacing these units, unfortunately they don't provide any warranties in my country so I'm stuck with this unit on my own.
I decided to disassemble Quest 3 and I found out that there is some oxidation, corrosion and burnout on a few pins of the depth sensor connector, this sensor is just a vcsel laser dot projecto located in the front of the headset in the middle between cameras. Due to its location under the air intake and in close proximity to the face and mouth, it can accumulate moisture/condensation from breathing, leading to connector corrosion and ultimately permanent damage.
I did a full teardown of the headset and didn't find any other traces of corrosion or moisture anywhere else. Turns out the only damage was on that connector of the depth sensor.
I decided to assemble it without the depth sensor and unfortunately Quest 3 still has no tracking. I suspect that this is because I removed the depth sensor and it just locks itself into a loop where it tries to startup cameras.
Software update can theoretically fix this issue if Meta realizes that they need to skip depth sensor checkout in the initial setup, it's really not needed for tracking as cameras can do SLAM without it. Just add an optional check for presence of a depth sensor, if Quest 3 does not find it because it is broken or disconnected, then just skip it and cameras will be able to work normally. Depth sensor is only used for guardian scanning (and for mixed reality), but this step can be done manually like in Quest 2 and Quest Pro. This is such a simple software fix that can get my (and maybe many more in the future) Quest 3 back to work. I did a few more tests and realized that if you disconnect proximity sensor the Quest 3 actually freezes on the Meta logo and goes into bootloop. Why do this? Isn’t it more logical to simply notify the user about a malfunction of the proximity sensor and put the displays in permanent on mode? The user will be able to turn off displays by putting Quest 3 into a sleep mode with a power button. The same issue when Quest 3 notices that there is no depth sensor, the entire tracking system freezes and the cameras can't turn on and the tracking stalls, moreover, it also blocks the connection to the controllers.
Please make changes to the software. It's unacceptable for the Quest 3 to just stall like that, users can read, just give them an error that something is not working as you did with the cooling fan.
As for a hardware fix, please Meta add a simple foam padding around the fpc connectors of the depth sensor, this will prevent any moisture accumulation inside. Smartphone manufacturers have been doing this for over dacade now.