Develop Bugs

USB disconnects my rooted kindle fire very fast (details inside)

I rooted my Kindle Fire about a month ago with KFU. Everything was fine until I turned it on one day and I got stuck at the Triangle screen. None of the reboot tricks work. The interesting thing which I think is what is stopping me from being able to successfully use other methods is that when I plug my Kindle Fire into my computer via usb, it connects, and then disconnects (the USB) about 2 seconds later. I've tried different ports, etc. Any help on this issue would be greatly appreciated. I've read over multiple things, but don't see a mention to the kindle being disconnected via usb so quickly, thus stopping me from being able to do anything.

Care to elaborate on what "reboot tricks" you've used?
What version of Windows are you using?

soupmagnet said:
Care to elaborate on what "reboot tricks" you've used?
What version of Windows are you using?
Click to expand...
Click to collapse
I've tried the rebooting the Kindle while trying to reset the kindle to booting "normally" within the KFU. I've tried holding down the power button on a reset, then pushing it again until it is orange, none seem to work. I'm confident I could get it to work again if the kindle did not disconnect from my computer so quickly. By this I mean I hear the "usb chime" when I plug it in, then within seconds the disconnect chime plays. During the brief few seconds it is connected, it shows up on my devices list, but obviously when the usb disconnect chime plays, it disappears off of the device list.
edit: I'm using windows 7 Ultimate.

Can anyone help me? I may add that My Kindle Fire was originally rooted with the KFU and worked perfectly fine. I literally turned it on one day, and it got stuck at the triangle screen. The connection issue of it disconnecting so quickly is what is stopping me from fixing it I believe. Please help.

ErikV55 said:
Can anyone help me? I may add that My Kindle Fire was originally rooted with the KFU and worked perfectly fine. I literally turned it on one day, and it got stuck at the triangle screen. The connection issue of it disconnecting so quickly is what is stopping me from fixing it I believe. Please help.
Click to expand...
Click to collapse
Read the first 3 posts here...
http://forum.xda-developers.com/showthread.php?t=1552547
Figure out what device drivers are getting loaded when the connect "chimes" sound in Windows. If you confirm that they are correct based on the contents above, you must stop the temporary fastboot, set the bootmode to normal using fastboot, and restart the device.
I suspect you've got more issues than just getting stuck on the bootloader though... If you are getting disconnect tones in the bootloader, that means it's attempting to boot into something, but obviously unable to do so.

kinfauns said:
Read the first 3 posts here...
http://forum.xda-developers.com/showthread.php?t=1552547
Figure out what device drivers are getting loaded when the connect "chimes" sound in Windows. If you confirm that they are correct based on the contents above, you must stop the temporary fastboot, set the bootmode to normal using fastboot, and restart the device.
I suspect you've got more issues than just getting stuck on the bootloader though... If you are getting disconnect tones in the bootloader, that means it's attempting to boot into something, but obviously unable to do so.
Click to expand...
Click to collapse
The disconnect tones are from my computer, the same tone when you unplug a usb (since the kindle is plugged in via usb) I can't change the bootmode because the usb disconnect chime happens literally 2 seconds later, and the kindle is disconnected, all the while the kindle is still on and showing the triangle screen.

ErikV55 said:
The disconnect tones are from my computer, the same tone when you unplug a usb (since the kindle is plugged in via usb) I can't change the bootmode because the usb disconnect chime happens literally 2 seconds later, and the kindle is disconnected, all the while the kindle is still on and showing the triangle screen.
Click to expand...
Click to collapse
Have you checked to see what drivers are getting loaded? Do you know what device should appear in the device manager? Have you tried to stop the temporary fastboot countdown? Do you know how to stop the temporary fastboot countdown?
If you aren't willing to try out my suggestions, there's not much else I can do.

kinfauns said:
Have you checked to see what drivers are getting loaded? Do you know what device should appear in the device manager? Have you tried to stop the temporary fastboot countdown? Do you know how to stop the temporary fastboot countdown?
If you aren't willing to try out my suggestions, there's not much else I can do.
Click to expand...
Click to collapse
Yes to all those things. The device does indeed pop up in the device manager but only for the brief 2 second window before it disconnects. I've tried multiple usb ports on my pc with the same result. The kindle does not power off in any way when the it disconnects from the pc.

ErikV55 said:
Yes to all those things. The device does indeed pop up in the device manager but only for the brief 2 second window before it disconnects. I've tried multiple usb ports on my pc with the same result. The kindle does not power off in any way when the it disconnects from the pc.
Click to expand...
Click to collapse
What is the device name that comes up?
What command did you send to stop the countdown?
What did it output as a result of the command?
What makes you think that it should power off when you disconnect from the PC?

kinfauns said:
What is the device name that comes up?
What command did you send to stop the countdown?
What did it output as a result of the command?
What makes you think that it should power off when you disconnect from the PC?
Click to expand...
Click to collapse
I've tried to reset the bootmode via the KFU method recommended in the guide posted here (normal, 4000 and trying to reset when it says waiting for device) The device pops up in the device manager as an "unknown device" which may be a problem with the version of the drivers im DLing. I'm using KFU version 0.9.6
When I first DLed them it seemed as if the drivers were installing correctly, when I plugged in the Kindle is said drivers were being installed but it failed because the device disconnected after the 2 seconds.

Rapid disconnects are nothing unique, they're simply driver or USB problems. Any malfunctioning USB device will give you that same sequence. Anyways, it's difficult to get out of a boot-loop without ADB so let's try to get that USB working again.
First, do you have a bootloader (like FFF) or a recovery (like TWRP) loaded? I'm not sure the USB driver will work during boot without at least one of those installed.
Second, boot into TWRP, then try to fix the USB from the computer end. Uninstall the drivers, download a fresh batch, reinstall drivers, reboot. Use explorer to check %userprofile%\.android\adb_usb.ini and make sure 0x1949 is there. Also check Kindle Fire Utility\drivers\kindle\android_winusb.inf and make sure whatever hardware ID is showing up in device manager is in there.
BTW, what device IS showing in Device Manager after the disconnect? Use right click, scan for hardware changes.
Third, the USB cable or ports themselves may be at fault. Try a different cable, and try a different computer. Also, reboot often.

hunterhk said:
Rapid disconnects are nothing unique, they're simply driver or USB problems. Any malfunctioning USB device will give you that same sequence. Anyways, it's difficult to get out of a boot-loop without ADB so let's try to get that USB working again.
First, do you have a bootloader (like FFF) or a recovery (like TWRP) loaded? I'm not sure the USB driver will work during boot without at least one of those installed.
Second, boot into TWRP, then try to fix the USB from the computer end. Uninstall the drivers, download a fresh batch, reinstall drivers, reboot. Use explorer to check %userprofile%\.android\adb_usb.ini and make sure 0x1949 is there. Also check Kindle Fire Utility\drivers\kindle\android_winusb.inf and make sure whatever hardware ID is showing up in device manager is in there.
BTW, what device IS showing in Device Manager after the disconnect? Use right click, scan for hardware changes.
Third, the USB cable or ports themselves may be at fault. Try a different cable, and try a different computer. Also, reboot often.
Click to expand...
Click to collapse
Thanks for your response, I will go through these and report back when I get back home from class.

ok, now I have my kindle being recognized by my computer as "android phone" with the sub of "android adb interface." If I have read the guide correctly that means it is in fastboot mode. However when I open kfu it says the kindle is offline.
If someone would be willing to help me out through Skype I would gladly appreciate it. I'm really at a lose as to what to do at this point.
and no stupidly I do not have FFF or TWRP loaded, since I first rooted it when I was a super noob. The usb driver seems like it should be able to work according the the Kindle fire beginners guide, but KFU does not recognize the kindle even though my computer does.

Phone not Mounting on PC

So my phone was mounting fine on my pc, and then all of a sudden it wasn't. My Nexus 7 still mounts properly and accepts developer commands, but the m8 won't (yes developer settings is on).
I tried wiping and flashing a rom clean and it still doesn't work, charges fine though. Any advice?

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I'm having the same issue. Stock non rooted and it will not connect. I have tried it on other computers cables ports everything.

Art2Fly said:
So my phone was mounting fine on my pc, and then all of a sudden it wasn't. My Nexus 7 still mounts properly and accepts developer commands, but the m8 won't (yes developer settings is on).
I tried wiping and flashing a rom clean and it still doesn't work, charges fine though. Any advice?
Click to expand...
Click to collapse
You might try a different cord.
Open Device Manager in Windows and then plug the phone in. Do you see it in the list with a little yellow triangle? Do you see Android USB Devices listed?

OP after literally messing with various driver files, 8 usb ports and 2 laptops, I dug out my old box of cables and found a taped up, on its last limb OEM HTC EVO 4g (not lte the original) cable. This thing has been through the ringer. But its exactly what It needed. I figured with the 3 cable I had already tried this wasn't the issue, but have you tried using an OEM cable? I guess that is all that works. Good Luck

beamer1341 said:
OP after literally messing with various driver files, 8 usb ports and 2 laptops, I dug out my old box of cables and found a taped up, on its last limb OEM HTC EVO 4g (not lte the original) cable. This thing has been through the ringer. But its exactly what It needed. I figured with the 3 cable I had already tried this wasn't the issue, but have you tried using an OEM cable? I guess that is all that works. Good Luck
Click to expand...
Click to collapse
Still trying to get it to work, have tried 4 cables myself. I might just end up having to return the phone.... Fastboot works in bootloader

Art2Fly said:
Still trying to get it to work, have tried 4 cables myself. I might just end up having to return the phone.... Fastboot works in bootloader
Click to expand...
Click to collapse
Uninstall all HTC drivers and HTC Sync. Then connect the phone. DO NOT choose the option to automatically install any drivers.
Open Device Manager, find the phone. Select the option to manually pick the driver, and select the generic MTP device driver.
This is what worked for me, after countless attempts at re-installing various HTC drivers, different cables and ports, etc.

Bump. Still looking for answer to this. I have RUU'ed both to Sense and Google Phone editions and the problem still persists, the phone does not detect its connected to a computer and change to mtp accordingly. Only way I was able to get the RUU in there was through fastboot, which is again the only time I can access the phone through usb. Adb is no luck in either android or recovery.

Art2Fly said:
Bump. Still looking for answer to this. I have RUU'ed both to Sense and Google Phone editions and the problem still persists, the phone does not detect its connected to a computer and change to mtp accordingly. Only way I was able to get the RUU in there was through fastboot, which is again the only time I can access the phone through usb. Adb is no luck in either android or recovery.
Click to expand...
Click to collapse
Have you tried revoking the USB debugging authorization and then accepting the RSA fingerprint key again when connecting to PC?
Obviously it can't be an USB cable problem if you can connect to it in bootloader mode and use fastboot commands.

To clarify, the phone just charges when connected, it does not detect that it is connected to PC so debugging doesn't even trigger, neither does mtp. I don't even get the slow charging notification

Does it do the same when you plug it in and reboot the computer to "pick up" during boot up process? Or if you run a live CD? I never had an issue like that with my phone but I did have a similar problem with the USB external blu ray drive I bought some time ago. The pc just didn't detect it at all not on any of the ports until I rebooted my PC with the drive already plugged it and for some reason it picked it up. <Not a solution as I don't know what caused it to not be detected in the first place but still...
Not sure if it's an issue with the device(Phone for you, blu ray drive for me) or if it's a problem with the PC even though other things might still work for you as it definitely did for me(phone, headset, mouse, keyboard, usb extender + all the external hard-drives connected to it)...

Problem exists in all computers, Mac, pc, linux

Did you try what I suggest in Post #6 above?
This worked for me when I had the same issue. adb and fastboot would work, but it would not mount MTP.
And just in the last day or 2 I helped someone else with the same issue and fix.

The phone doesn't show up in device manager.

Have you modify the Kernel? (Applying some settings for example)
I browsed over the web for this issue and found some people with the same problems. They solved by removing the settings applied on the kernel or flashing a new one.

I've flashed various kernels and ruu, still same result

Still looking for help

[Q] Can't connect to the PC

I have had issues connecting the Note 4 to my PCs. I have tried multiple cables and computers. A usb error appears "Usb Device not recognized" "The last USB device you connected to this computer malfunctioned and WIndows does not recognize it." All PC's are running windows 8. I have tried connecting it via fastboot to flash to stock as well as through ADB and I cannot get anything to read the device.

Are you using the oem cable? Sometimes cheap generic cables give errors. Enable usb debugging and see if that helps. Good luck.

dteze88 said:
Are you using the oem cable? Sometimes cheap generic cables give errors. Enable usb debugging and see if that helps. Good luck.
Click to expand...
Click to collapse
Thanks but I've tried multiple. OEM and aftermakert cables. I found that when I put it in the charger it doesn't detect it as AC. I believe for some reason when the phone is connected to the PC it doesn't switch to MTP, which could cause the issue. I have wiped the phone, tried different roms, and installing plasma kernel. I am at my wits end. I have tried finding sprint's seceret number to dial, supposedly there's a menu to force MTP but I can't find it anywhere.

OK. So I couldn't connect via cable I tried flashing the stock image though mobile odin and now I lost recovery and the phone bootloops. Does anyone know a way to boot into recovery from the external SD card?

I would just flash the OF5 tar and start from scratch. http://forum.xda-developers.com/not...om-sm-n910p-stock-of5-odin-flashable-t3158114

Sounds like it's your computer.
Edit: Any other phone's Samsung or not able to connect? Does your phone charge with any or all of your cables? Hopefully the stock cable.

You need to go to Device Manager and Uninstall/reinstall the drivers pertaining to USB
Uninstall the samsung drivers
After that, unplug your powercord from the laptop
connect the phone to your usb port first and then replug your powercord and turn on your laptop
let the usb and samsung drivers reinstall(auto or manual)(if it detects it normally))

dteze88 said:
I would just flash the OF5 tar and start from scratch. http://forum.xda-developers.com/not...om-sm-n910p-stock-of5-odin-flashable-t3158114
Click to expand...
Click to collapse
I wish I could, the issue is that since I get this USB error, I can't get ODIN to detect my phone.
w7excursion said:
Sounds like it's your computer.
Edit: Any other phone's Samsung or not able to connect? Does your phone charge with any or all of your cables? Hopefully the stock cable.
Click to expand...
Click to collapse
I was able to get my Note 3 to connect with no problem, I was even able to get ODIN to detect it in Fastboot. I have one more cable I am going to try tonight, I have my girlfriend bringing it with her. I may have switched an S4 cable with the Note 4 cable. I hope this is the case.
xxSTARBUCKSxx said:
You need to go to Device Manager and Uninstall/reinstall the drivers pertaining to USB
Uninstall the samsung drivers
After that, unplug your powercord from the laptop
connect the phone to your usb port first and then replug your powercord and turn on your laptop
let the usb and samsung drivers reinstall(auto or manual)(if it detects it normally))
Click to expand...
Click to collapse
I was using my desktop, and I tried this on my laptop. Didn't work. Thanks though! I am wondering if this possibly could be a Windows 8.1 issue...
Anyways, 5.50 to anyone who gets this working.

I accidentally switched cables with my son's s4 and nothing would work. Figured it out and then I could connect to my computer. Could be the same thing lol.

w7excursion said:
I accidentally switched cables with my son's s4 and nothing would work. Figured it out and then I could connect to my computer. Could be the same thing lol.
Click to expand...
Click to collapse
I wish that was the case. I am wondering if it's a windows 8 issue now.

I'm on 8.1 pro, and my devices detects fine under cm12.1.
Have you tried going into Settings > Storage. select the 3 dot menu on the top right and force MTP or PTP detection while device is connected to PC / Laptop?

adb reboot recovery, now FTV is dead

I just did "adb reboot recovery" and my FTV1 turned off and never came back on. Unplugged everything, plugged back in, nothing. Then I went to the bedroom where there's another FTV, and its dead also. How did I do this and is there a fix?
edit: by dead I mean it wont even power on. Neither FTV can get to the first white amazon logo. No video output, no light on the front.

Try plugging into your computer and monitor the status of the USB device drivers being loaded. If the computer seems to be recognizing it, try 'adb devices' or 'fastboot devices ' to further check the status of the device. A simple 'adb reboot' or 'fastboot reboot' may get it booting again.

mrlaugh01 said:
Try plugging into your computer and monitor the status of the USB device drivers being loaded. If the computer seems to be recognizing it, try 'adb devices' or 'fastboot devices ' to further check the status of the device. A simple 'adb reboot' or 'fastboot reboot' may get it booting again.
Click to expand...
Click to collapse
Do you mean connect the FTV to my pc? with USB? Not sure I have a cable like that (fat usb on each end). The FTV is not the slightest bit warm when the power cable is plugged in so I doubt I can adb to it.

It can't hurt to try the USB a to USB a cable thing. If your stuck what do you have to lose? Were you rooted/ unlocked / and on a pre-rooted rom?

Michajin said:
It can't hurt to try the USB a to USB a cable thing. If your stuck what do you have to lose? Were you rooted/ unlocked / and on a pre-rooted rom?
Click to expand...
Click to collapse
I'll have to get one of those cables. Does quality matter? Found it direct from China for under $1: http://www.ebay.com/itm/30CM-High-S...ata-Transfer-Charger-Cable-Cord-/282210741043
I was on rbox's latest pre-rooted rom. I updated the FTV1's on different days yet they both died at about the same time. Right after I gave one of them the adb command "reboot recovery."

I misread your post and was under the assumption you were using a Fire Stick. But USB ADB should be possible. Here's a quick search result: https://developer.amazon.com/public/solutions/devices/fire-tv/docs/connecting-adb-to-fire-tv-device

mrlaugh01 said:
I misread your post and was under the assumption you were using a Fire Stick. But USB ADB should be possible. Here's a quick search result: https://developer.amazon.com/public/solutions/devices/fire-tv/docs/connecting-adb-to-fire-tv-device
Click to expand...
Click to collapse
sorry for delayed response, was out of town and didnt want to think about my two FTV paperweights.
I looked at that link and it says this:
"If you plan to connect your computer to your Fire TV device using a USB cable, turn on USB Debugging."
I never did USB debugging so I never turned that on and even if I did I'm fairly certain the FTV is not turning on since its not even slightly warm. Do you think I should order the USB A to A cable anyway and try?
I cant believe I'm the only one that has had this happen...

Yes I believe it'll work still... The Fire devices have a system 'adb mode' when it first boots up. Booting up TWRP on a Fire Stick is a similar process you can probably follow. But if you're not getting my power, or it's not not powering up, you may have bricked it.

Pixel 2 XL not connecting to PC

UPDATE:
I ended up just returning the phone and getting a new one (it was an Ebay seller so they didn't try to repair it).
New one connected instantly and I can use ADB and Fastboot perfectly.
Definitely something wrong with the first one, weird how the headphone adapter and OTG worked though.
Original post:
I know there are other threads on this but I really need some help on this.
I just got a Pixel 2 XL, but it won't connect to the PC. At all. No connection noise, nothing in task manager. The only change between plugged and unplugged is that the phone starts charging. No notification appears when I plug it in, it doesn't even try to connect.
I've tried three different cables, three different PCs, I've fiddled with USB debugging. I can't do anything with drivers on Windows because nothing changes in device manager when I plug it in.
I don't have any computers with USB C ports so I can't test that but I've tried all different ports on my PC (USB 2 and USB 3).
The headphone adapter works and when I plug in my old HTC U11's earbuds it says "accessory not supported" (which it's supposed to say, those earbuds only work on specific phones) so the port can't be completely broken.
I also tried plugging a USB drive into the full size to C adapter that comes with it and it reads it perfectly. I copied my music library onto the Pixel by putting it on a flash drive first.
I realise it may just be defective but it would be a huge pain if I got a new one only to discover that it was something that I'm doing or my PC causing it. And is it even possible to be defective when it can output music and even transfer files from a flash drive through that same port?
What else can I try?

megaman1574 said:
I know there are other threads on this but I really need some help on this.
I just got a Pixel 2 XL, but it won't connect to the PC. At all. No connection noise, nothing in task manager. The only change between plugged and unplugged is that the phone starts charging. No notification appears when I plug it in, it doesn't even try to connect.
I've tried three different cables, three different PCs, I've fiddled with USB debugging. I can't do anything with drivers on Windows because nothing changes in task manager when I plug it in.
I don't have any computers with USB C ports so I can't test that but I've tried all different ports on my PC (USB 2 and USB 3).
The headphone adapter works and when I plug in my old HTC U11's earbuds it says "accessory not supported" (which it's supposed to say, those earbuds only work on specific phones) so the port can't be completely broken.
I also tried plugging a USB drive into the full size to C adapter that comes with it and it reads it perfectly. I copied my music library onto the Pixel by putting it on a flash drive first.
I realise it may just be defective but it would be a huge pain if I got a new one only to discover that it was something that I'm doing or my PC causing it. And is it even possible to be defective when it can output music and even transfer files from a flash drive through that same port?
What else can I try?
Click to expand...
Click to collapse
Which version of Windows are you trying it on? Can you try it on a Win 7 machine? It's not the phone but the drivers. There are various threads around that will guide you thru it but you have to search some. Some are a little old but they should work. Keep at it, you'll figure it out. There is something in device manager that you need to tinker with if I recall correctly. Happened to me on my Pixel OG and it took me a few days to finally figure it out. Total pain but relief once you get it.

If you have a relatively new computer (Win 7 or newer) then it *should* recognize the Pixel. But sometimes Windows can be a pain in the ass. Download & install Android SDK which will install the latest Android USB driver, reboot the computer, then connect the Pixel again.

sublimaze said:
If you have a relatively new computer (Win 7 or newer) then it *should* recognize the Pixel. But sometimes Windows can be a pain in the ass. Download & install Android SDK which will install the latest Android USB driver, reboot the computer, then connect the Pixel again.
Click to expand...
Click to collapse
I don't think I can install any drivers unless the phone shows up as something in device manager, which mine doesn't

megaman1574 said:
I don't think I can install any drivers unless the phone shows up as something in device manager, which mine doesn't
Click to expand...
Click to collapse
Your computer must have Android USB driver installed before it will recognize the phone.

sublimaze said:
Your computer must have Android USB driver installed before it will recognize the phone.
Click to expand...
Click to collapse
I'll search this in the morning. He needs to uninstall something.. dang it I forget. I'll figure it out tomorrow. Or search my posts from a year ago I'm sure it's there somewhere.
Sent from my Pixel 2 using XDA-Developers Legacy app

sublimaze said:
Your computer must have Android USB driver installed before it will recognize the phone.
Click to expand...
Click to collapse
What I mean is it doesn't show up at all. When I plug the phone in device manager doesn't change.

bobby janow said:
I'll search this in the morning. He needs to uninstall something.. dang it I forget. I'll figure it out tomorrow. Or search my posts from a year ago I'm sure it's there somewhere.
Sent from my Pixel 2 using XDA-Developers Legacy app
Click to expand...
Click to collapse
I had a look through your post history but I'm not sure what I'm looking for... And I can't figure out how to search a post history

megaman1574 said:
I had a look through your post history but I'm not sure what I'm looking for... And I can't figure out how to search a post history
Click to expand...
Click to collapse
Yeah I know, only goes back for like a year or so. This is the guide I followed and it worked. Some still had problems but check out the OP and give it a shot.
https://forum.xda-developers.com/pixel-xl/how-to/guide-fix-mtp-driver-windows-10-t3570625

This may be silly but when my phone was new I had the same issue. I had to go into the USB settings on my phone and change them from charging to file transfer.

I'm having similar issues to the OP, but I've had my phone since it was released. I have done everything known to man to try and get this working--updated Android Studio/drivers, both fixes listed HERE, tried numerous cables, rebooting phone and multiple PCs, still not getting my phone to get recognized at all.
My exact issue is this: I'm still on the August 2018 Security patch, so I wanted to update to October. Downloaded my files then went into Magisk and uninstalled (un-root) restoring stock boot. I waited a few hours before I could try to flash the OTA, but once I did, I connected the phone (USB-C to USB-C OEM cable) to my PC and it successfully connected in Debug mode. Ran "adb devices" and phone was seen. "adb reboot bootloader" successfully rebooted phone, but it did not go into bootloader mode for some reason, it just restarted in normal mode. The only problem is now the phone doesn't talk to my PC no matter what.... the USB-C to USB-C OEM cable doesn't even charge the phone let alone connect to give me file transfer options. If I try a USB-C to USB-A cable, the phone charges but the PC doesn't recognize my phone is connected. Debugging never works. Even my Car Charger (which is USB PD capable) doesn't charge the phone, I have to go back to my regular USB-C QuickCharge car adapter to get it to take a charger. I've disabled Debugging, changed default USB connection type to File Transfer, PTP, etc.
So, is there a way I can try to flash the OTA without connecting to a PC? Maybe even just flash the August Boot.img? I want to try updating the phone to see if that fixes my issues first. I am currently with an unlocked bootloader, no root and stock recovery, so I don't believe Flashify will work without getting root back... I think when I restored my stock Boot via Magisk, it FUBARed something. The only thing I can try is to use my USB-C to USB-A cable and see if fastboot recognizes the phone with that cable... the USB-C to USB-C cable is no dice in Fastboot.

Do you have another Android device? If so, (and it is rooted), you can run adb and fastboot from there. The binaries are available via the Magisk repository. Just grab a terminal emulator and a usb-otg cable and go to town. No driver issues, no fuss, no mess.
I was occasionally successful with a usb-c to usb-c cable, but sometimes the devices would get confused. The otg cable works every time, with the host end facing the adb/fastboot running device.

@hawkjm73 To whom are you talking to? If me, I don't have an OTG cable nor another rooted phone.
I did try the USB-A to USB-C cable and booted into Fastboot, which worked. I was able to at least boot into TWRP and get Magisk re-installed so I'm rooted. I booted the phone back up and still no USB recognition or Debugging. I'm going to wait to try a third PC to see if that will work in getting Debugging/ADB commands to work. All else fails, I'll just do a full Factory October flash without the wipe.
What's puzzling to me is why this all happened and why even my USB-C PD car charger won't work. Something strange is going on.
---------- Post added at 03:01 PM ---------- Previous post was at 02:25 PM ----------
Update: I grew impatient and decided that since my PC was seeing the phone in fastboot, I flashed the full October Firmware manually in fastboot (ran each command in the flash-all.bat one by one). As soon as it booted into the OS, Debugging and USB connectivity (both cables) turned back on. I haven't tested my Car USB PD charger, but I suspect that will work too.
I'm guessing when I uninstalled Magisk and tried restoring the stock Boot.img, something went awry and it was causing the connectivity issues.
So, if you can get your phone into Fastboot and your PC recognizes it, I would suggest a full system image flash, don't forget to remove the -w if you don't want to wipe.

megaman1574 said:
I know there are other threads on this but I really need some help on this.
I just got a Pixel 2 XL, but it won't connect to the PC. At all. No connection noise, nothing in task manager. The only change between plugged and unplugged is that the phone starts charging. No notification appears when I plug it in, it doesn't even try to connect.
I've tried three different cables, three different PCs, I've fiddled with USB debugging. I can't do anything with drivers on Windows because nothing changes in device manager when I plug it in.
I don't have any computers with USB C ports so I can't test that but I've tried all different ports on my PC (USB 2 and USB 3).
The headphone adapter works and when I plug in my old HTC U11's earbuds it says "accessory not supported" (which it's supposed to say, those earbuds only work on specific phones) so the port can't be completely broken.
I also tried plugging a USB drive into the full size to C adapter that comes with it and it reads it perfectly. I copied my music library onto the Pixel by putting it on a flash drive first.
I realise it may just be defective but it would be a huge pain if I got a new one only to discover that it was something that I'm doing or my PC causing it. And is it even possible to be defective when it can output music and even transfer files from a flash drive through that same port?
What else can I try?
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Time for an RMA...just happened to me a month ago

WoJ... good follow-up update.

I ended up just returning the phone and getting a new one (it was an Ebay seller so they didn't try to repair it).
New one connected instantly and I can use ADB and Fastboot perfectly.
Definitely something wrong with the first one, weird how the headphone adapter and OTG worked though.