Oneplus 3T intermittent phone call issues
I’ve been working on repairing a Oneplus 3T and noticed that it is having intermittent issues with making phone calls. Sometimes when making a phone call there will be no sound coming from the ear speaker and the person on the other end of the phone call won’t be able to hear me talking.
At first I assumed this might be a microphone issue so I went ahead and replaced the lower PCB with the headphone jack, USB-C port, and microphone is for the phone. That didn’t seem to help but was worth doing as the phone had faulty pins in the USB-C port anyway.
With no luck there, I thought maybe it was a software issue. A lot of people suggested clearing the phone cache which I tried to no avail. After that I decided to try LineageOS to see if that would work better, but I had the same issue there.
I’m at a loss at this point what the issue could be. I’ve verified that the new microphone is functional so I know that isn’t the issue at this point. My only other guess is that there’s some other piece of faulty hardware. I noticed during a phone call that I was hearing some crackling from the ear speaker so I’m wondering if maybe that could maybe be having a hardware failure that causes the phone app to malfunction. In OxygenOS the phone would typically reset and enter a bootloop after a phone call. It didn’t seem to do that with LineageOS but occasionally the phone app would crash.
It may be worth noting that the phone app works fine when using a pair of earbuds, although I cannot confirm that the earbuds actually had a microphone or not.
Thanks in advance!