No Boot - No Recovery - No Download Mode Unbrick Guide
Qualcomm HS-USB QDLoader 9008 or Secure booting error (No Boot - No Recovery - No Download Mode) or "QHSUSB_BULK"
Hi team, if you have come here I'm sorry you are having this problem! But my friend and I have been to hell and back trying to fix this problem and we wanted to share our method of success for any poor soul who is experiencing the same thing! For our situation the USB was unplugged half way through flashing a KDZ or going back to stock firmware and created the No Boot - No Recovery - No Download Mode problem.
This has only been tested on the D855.. Just so you know.
First off, here are some links which you may need to have a look at if you have not done so already. Most of the bricking problems have already been extensively talked about by people here on XDA. For the method that works, we had to pull information from everywhere and spent a long time looking for the solution.
How to go back to stock - http://forum.xda-developers.com/showthread.php?t=2785089
Link for TOTs and KDZ's from the above thread - http://storagecow.eu/index.php?dir=Xda/LG+G3/Stock/
The Main Fix for the problem - http://forum.xda-developers.com/lg-g3/general/fix-unbrick-lg-g3-stuck-qualcomm-hs-usb-t2933853
The G2 version of the fix (for reference if you still have problems 55+ pages) http://forum.xda-developers.com/lg-g2/general/fix-unbrick-lg-g2-stuck-qualcomm-hs-usb-t2933830
This is your last stop shop if everything is broken and nothing works, involves hardware fix - http://forum.xda-developers.com/sprint-lg-g3/general/guide-fix-hard-brick-recovery-guide-t3132359
The problem we encountered several times with all of the described methods above, is that many do not describe important things. While the main fix thread for the Qualcomm HS-USB QDLoader 9008 mode, which is shown in device manager, is very well written and detailed, the programs which are linked in this thread are questionable and haven't worked for many users with some offering to fix for money. We searched the internet and located a working version of the program which worked without giving a "Device was not found in dload trying to flash programmer" like the one provided on the XDA page. Use the links below for a working version from this thread http://androidforums.com/threads/lg-g2-not-turning-on-help.916865/
My first point is if you are having problems with any of the things, CHANGE YOUR USB CABLE or use the stock cable (I know most experienced users know this). The reason for this problem has something to do with different USB cables being made for different purposes and are of different qualities. Having an error on the USB ports gave us only qhsusb_bulk on windows device manager, without Qualcomm HS-USB QDLoader 9008 as well.
If you are still having problems, check your USB ports. It is really important to make sure this isn't the problem or you will be trying to fix this problem endlessly.
First attach the USB cable to the computer. When you plug your phone in, make sure you attempt to enter download mode by holding the volume up button when you plug the USB into your phone. Even though the phone will not enter "Download Mode" It will allow the phone to be detected by your computer (at which point you can release the buttons, it should then show "Qualcomm HS-USB QDLoader 9008" under ports. If this is not displayed you have a problem with the USB cable or port, or your phone is hard bricked and you need to head to the above guide for the hardware fix. If you have followed so far and are wondering what to do from here, once the "Main Fix" guide ends, head over to the "How to go back to Stock" thread above. Your phone should be showing "firmware upgrade" and you can proceed to flash a new updated KDZ on your device then everything will work and your nightmare should be over!
Working Boarddiag - https://drive.google.com/file/d/0BzkqP9M0LLWQUkEyRkZrVHlEbDg/view
Qualcomm USB Drivers (Essential for the aforementioned "Main Fix" above) - https://drive.google.com/file/d/0BzkqP9M0LLWQblF6Vl9OcUkwUDA/view
LG United Drivers (Phone Drivers) - https://drive.google.com/file/d/0BzkqP9M0LLWQUURDTHlYOW5YRms/view
If this helped you to fix your nightmare don't forget to hit the thanks button!