My mobile goes into fastboot mode whenever it is restarted. I need to connect it with laptop to run 'fastboot continue' command to start it. Any solution to fix it permanently?

@undef It's Once plus one. Though I can't deny any possibility as I've less knowledge of hardware. But I feel there is some other problem because;

1. In this situation, if USB cord is connected then it never start. I need to keep micro USB port free.

2. From last 3-4 days it stuck in OS loading and I need to try fastboot continue many times.

I feel it is somewhere related to heating because... ( I know you're gonna laugh now) last year I put a cup of hot tea on it's back and then problem started. However it can be just a coincidence and nowhere related. but don't know

@amitgupta
The cup of coffee ☕ won't do such bad things 😝 😂

Is the volume up/down button stucked?
You can enter recovery on start?
What happens after recovery > reboot to system?

You could try reflashing, too... 🤔
Is fastboot unlocked?

Seems there are 2 possibility:

1) problems with col. Button.

2) bootloader may be damaged.

@Irithyll

s the volume up/down button stucked? No.

You can enter recovery on start? Yes

What happens after recovery > reboot to system? Same situation

You could try reflashing, too... 🤔 I've replaced Android with LineageOs when the problem started. The problem still persist.

Is fastboot unlocked? I don't how to check this.

@undef I had already tried factory reset then installed LineageOS when the problem was started (11 months ago). But no help.

Is there any way/trick I can check on volume button without opening the mobile.

@canonbolt can we confirm about bootloader with some application?

@amitgupta I highly doubt about checking BL with any application, give a shot on installing new BL.

In my opinion simple way is to go to local mobile shop and ask them if vol. button is under pressure or what.

@undef trying with howtogeek tutorial :fingercrossed:

I've already TWRP installed on my phone does it mean that the bootloader is already unlocked? (because somewhere I read that you need to unlock booloader to install TWRP)

@amitgupta I have a OnePlus as well. Under developer settings you have to turn off "advanced reboot"

@NULLmaster I've the option "Advanced restart". but it is already off :(

After resetting my mobile, it is at least not being stuck after fasboot continue and not being restart automatically. However fastboot problem is not solved yet.