Trouble Using Bootloader Exploit

[PopeXXIII]

Hello to whoever might be listening. I'll try to detail my situation and maybe someone will have insight into why this isn't working.

I have the following:

USB power adapter from the Chromecast box
Prefab OTG cable
Homebrew OTG cable
USB stick imaged on OSX
USB stick imaged on Windows 7

Soldered a couple male USB connectors and a female USB connector to rig these items together in various configurations.

While holding down the Chromecast button, the best I get is a couple blinks out of the USB sticks. It seems like something is happening, but it doesn't kick off the entire imaging process.

Both OTG cables work to connect a mouse to my Nexus 7.

Any ideas?

[coggy9]

What is your firmware version? Google might have pushed an update. You can check in the Windows/OSX app. http://i.imgur.com/xBo7aC6.png

[PopeXXIII]

Same. 12072.

[garhomes]

I have the same issue, maybe a blink or two on the stick followed by a few colored dots on the right side of the screen. You can actually see the screen I am talking about in the video posted in the gtvhacker blog: http://www.youtube.com/watch?feature=pl ... W38nEleiBM I have tried different power supplies/usb sticks to no avail. Purchased my OTG cable from atomicmarket a few years ago, I assume that's where the issues lie.

[PopeXXIII]

I assumed it was my OTG cable too. That's why I busted out my soldering iron and made a fresh one myself. Same result. A couple blinks and colored dots on the screen.

[garhomes]

I have the same issue, maybe a blink or two on the stick followed by a few colored dots on the right side of the screen. You can actually see the screen I am talking about in the video posted in the gtvhacker blog: http://www.youtube.com/watch?feature=pl ... W38nEleiBM I have tried different power supplies/usb sticks to no avail. Purchased my OTG cable from atomicmarket a few years ago, I assume that's where the issues lie.

EDIT: FIXED! Ran through the same dd.exe process in Ubuntu, worked perfectly when I tried it. I originally used Win7, so maybe there is some problem during the writing process. Now you know! Use Linux.

[PopeXXIII]

$#@! Spent the last couple hours getting Linux running to make sure the image is written to the USB drive 100% properly. Now my Chromecast goes to the Updating splash screen, even if I'm holding down the recovery button. I'm not letting it run the update in hopes I can still get root access. It will be collecting dust until there is a solution. Grumble.

[PopeXXIII]

So, I am ripping my Chromecast apart.

What's the easiest way to attach leads to the UART pins?
Might there be some information gained from an update process log that might lead to another exploit vector?
Any brute force way to short out the device and get the update to fail? I'm willing to risk frying the device.