I was working with “ROM Manager” today on my LG P500 phone and saw a update available for ClockworkMod Recovery available. Just clicked on the  update and the next screen asked me to choose the Phone Model. Selected the one which I thought was my model and it finished the update. I rebooted into recovery to check if everything was alright? And guess what, Phone on rebooting greeting me with Fastboot screen i.e. a black screen with the following message :

fastboot mode started
udc_start()

Now I knew that the something went wrong while updating the ClockWorkMod recovery using the ROM Manager. Perhaps the model selected by me during the update was not the exact one and hence a wrong ClockWorkMod recovery got flashed.

Thanks to a tutorial by arvinoids at XDA forum, I was able to unbrick my Phone.

How to Unbrick LG P500 stuck at fastboot mode

The phone screen stays at the black screen with the fastboot mode message. If you connect the phone to your computer using a USB, you will see additional messages e.g suspend, portchange etc. on the phone screen.

fastboot mode started
udc.start()
-- suspend --
-- reset --
-- portchange --
-- reset --
-- portchange --

Pre-Requirements:

Before you can start with, you need to install Android SDK & Java JDK on your PC along with some other things like the USB drivers and the Recovery image. Complete the following requirements which are needed for unbricking your phone from fastboot mode.

  1. A Windows PC with Phone USB Cable to connect your Phone to PC.
  2. USB drivers for your LG P500 phone (use B2C from LG). Without these drivers, PC wont detect your phone which is needed to run the commands to reinstall recovery.
  3. Android SDK (download from here)
  4. Java Platform (JDK), required to run the Android SDK
  5. ClockWorkMod or AmonRa Recovery. (I have used Amon Ra recovery for my Phone)

Procedure to unbrick

Now, unzip the recovery image  (Recovery.img) from the zipfile just downloaded above in step 5. You need to save this Recovery.img file in the Android SDK tools folder (located inside Prog. files/ Android SDK/tools) . If you are on a 64 bit operating system, the location will be diff with a small difference of folder Prog files (x86) instead of just prog. files.


Just check if fastboot.exe file is located in the same tools folder or not. You may also need AdbWinApi.dll duringthe next steps. If files are not there, download both the files from links below.

Download: fastboot, AdbWinApi

Now, Connect your Phone to PC using the USB cable. PC should detect your phone if the USB drivers are installed properly. If all is well, you will get the messages on the phone screen, about which we talked about above e.g suspend, portchange etc . Now open command prompt or DOS window on your PC. Just navigate to the Android SDK tools directory using the cd.. or cd command. Checkout the screenshot below to see if you are not sure of what I want to say here.

Now you need to run the following commands one by one in the command prompt window.

fastboot erase recovery
fastboot flash recovery recovery.img
fastboot reboot

Hopefully, you wont get any error message while running the above three commands. If every command is executed successfully, your phone will reboot into recovery. Just reboot and you will get back to your working phone without any data loss.

Update:

If you still face issues like your Phone is not being detected, try the following: (updated from comments below).

Download PDANET desktop that includes an special LG driver that enables your PC to read the smartphone. Install it and then connect your phone to PC. Navigate to Device Manager and  you will find a a yellow question mark against android driver listing. Right click on that and select update driver. After the update, PDAnet will recognize your device & will install the driver. After this, your Phone will be detected by your PC.

Source: XDA