[Sprint LG Optimus G] Lack Thereof:
Optimus G softbricked, flashing fails with partition table error

Well, it looks like questions posted here don't usually get replies, but I'll try anyway. I've given myself a 72 hour crash course in android flashing and debugging, but still am coming up empty.

I've got an Optimus G that seems to be softbricked. It boots as far as the LG logo after the animation, and then sits there forever getting hot.

I've attempted to flash it with LGNPST, following instructions in the teenybin thread over in the dev board. Everything appears to work properly right up to 85%, when it gives me the error:

Fail to write Partition PRIMARYGPT, 256th Sector

I've repeated the process with both full stock BINs (SV9 and SVB) as well as teenybins (SBL_Unlock and ZVBin), and I get the same result no matter what. I have also tried using LG Flash Tool, following instructions from the LG Flash Tool thread, and it fails with word-for-word the same error; it just fails much much faster than LGNPST.

From my searches of the forums, I've found 2 or 3 posts of people who've encountered the same problem over the years, but haven't found any posts of how they got around it. One solved his problem by going to teenybin... that didn't work for me.

--- Full Disclosure and Backstory ---

I got the phone used. It was booting fine, but still had previous owners info, settings, apps, etc. loaded, and I wanted to do a factory reset before activating it on my MVNO. The factory reset button in the settings menu was not responding, so I followed instructions from the Sprint website to accomplish this. I powered down the phone, and then pressed power + volume down, which gave me access to a "system recovery <3e>" menu, from which I performed the factory reset.

The reset appeared to complete successfully, but the phone has not been able to boot since. It will sit at the LG logo and act as a space heater until I shut it off or the battery goes dead, whichever comes first.

When the phone WAS booting, I did not think to look at or record what firmware etc. the previous owner had been running. I only poked at the menus enough to decide I wanted to start fresh.

--- What I CAN make the phone do ---

I can get it into download mode.

I can get it into the volume down + power "Android System Recovery <3e>" menu. From there, there is an "apply update from ADB" option that I have investigated. Selecting that option makes the phone prompt me to

Now send the package you want to apply to the device with "adb sideload <filename>"

After reviewing more info online, I thought that perhaps I could sideload a stock ROM using this option, but have hit some hefty brick walls investigating that option. Unfortunately when I have the phone in that mode, Windows Device Manager feeds me

Windows has stopped this device because it has reported problems. (Code 43)

A request for the USB configuration descriptor failed.

Drilling down into the Details tab and checking the hardware ID shows only "USB\CONFIG_DESCRIPTOR_FAILURE" where a device ID should be, and I'm unable to get any driver to recognize it, either the official Google USB driver, the LG usb driver, or the naked driver found on these forums. Thus ADB doesn't see the device. I suspect, but have no proof, that USB debugging was disabled when I performed the factory reset, so this menu option may be broken until I can re-enable it. Again, I'm new to this stuff and only speculating; Google and the forum search has only suggested that I try a different USB cable and port, and I have tried several combinations (currently using an OEM HTC cable, new out of shrink-wrap, plugged into a USB 2.0 port).

--- What I CAN'T make the phone do ---

It won't go into the "fastboot" screen that forums say you can access by pressing Volume Up + Power. Pressing that combination flashes the LG logo briefly, and then the phone goes dark and stays dark.

Thanks for reading; here's hoping for replies.