Windows Device Recovery Tool cannot see my Lumia 640 - Microsoft Community

windows 10 mobile (release preview ring) says there update. 

choose install

stuck on rotating gears more hour

reboot power key, phone stuck @ windows logo, after hard reset (vol+,vol -,power,vol -)

run windows device recovery tool 3.11.34101

choose model, install

stuck @ switching phone flash mode

reboot power key 

now phone cannot detected pc. if boot while connected pc,  first connect unrecognized usb device, after second or two, disconnects. never stay connected long enough windows device recovery tool detect.

if switch exclamation mark mode (vol - while starting), phone shows exclamation mark 6 seconds reboot itself.

*** moderator's note: post moved appropriate forum category. ***

hello sheng,

regarding concern, try resetting phone doing following:

1. press , hold the volume down and power buttons @ same time until feel vibration (about 15 seconds).

2. when feel vibration, release buttons, , press , hold the volume down button until see large exclamation mark.

3. once exclamation mark appears, press following 4 buttons in order: volume up , volume down , power , volume down . phone should reset , restart itself.

important: lose data on phone after resetting it.

if issue persists after doing steps above, recommend in touch b2x support further assistance.

feel free post if have other questions.

Windows Insider Program / Windows Insider Preview / Performance and maintenance / Phone