8 replies to this topic

[GnatGoSplat]

I wanted to try Dhacker's Kitkat 4.4 soooo bad, but my RAZR M was on the newest OTA and un-unlockable. I thought hmmm... if the bootloader unlock exploit targeted the TrustZone partition and the OTA patched out the TZ exploit, maybe I can downgrade the TZ partition to bring it back! So like the idiot that I am, I "dd" the old tz.mbn into /dev/block/mmcblk0p7. Attempted to reboot to see what would happen, and well, brick happened. So yeah, don't do that.  It's so dead, it acts like it has no battery.  Obviously, I'm a moron and should leave the hacking to the hackers.

Anyway, is there a way to JTAG it back, or is my only recourse to use it as parts to fix a phone with a cracked screen or something?

Also, I'm not smart enough to know why it won't boot with a downgraded TZ partition. Just to satisfy my curiosity, Is a hard-brick what happens when the "chain of trust" is broken? Could it have worked had I downgraded every single partition involved in the chain of trust, or am I super far off base?

 

[johnthehillbilly]

Will it not even boot to AP Fastboot?

[GnatGoSplat]

Nope, it had 100% battery when it died, but now it acts completely dead.  No lights, no vibrate, no sound.  Pushing buttons, holding down buttons, plugging in USB, holding down buttons and plugging in USB at the same time, none of it does anything.  No signs of life, it's completely dead.  Just like if it had no battery in it.  Doesn't even get warm if I leave it plugged in, so the charging circuit won't even start.  Someone on another forum suggested the factory cable, but from what I've read, that seems to be for an alternative way to power phones whose battery died.  My battery should be 100%.

[johnthehillbilly]

A factory cable may actually help you.... as it powers the main board directly..... basically, if the phone cannot draw power from the battery (due to software not telling it to)... then obviously the phone won't power on.... .... it would be worth it in my opinion to try a factory cable..... and try flashing again

[GnatGoSplat]

I tore apart a mini-to-micro adapter and wired up pin 4 to pin 1 as this tutorial shows.

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Verified +5V on both pin 1 and 4.
Nothing.

 

I think it's dead.

May just have to use it as parts to fix a phone with a cracked screen.

Just guessing, but I think to get into AP Fastboot or even for the bootloader to launch, it probably requires an unbroken chain of trust and my downgraded TZ partition breaks the chain so it doesn't even try to start the bootloader. Just guessing though.  Can't help but wonder if I'd dd-flashed every single partition involved in the chain of trust if that would have worked to downgrade. Dangerous thoughts that could lead me to a 2nd bricked phone in the future... I'd better just get that idea out of my head!

[GnatGoSplat]

After months of my phone being bricked, I decided to plug it into USB and the green light came on and it shows signs of life.  No picture on the display, but it shows up as USB Input Device, shows as "HID-compliant" in device manager. Hardware ID is VID_05C6, PID_F006.  All I could find is the VID belongs to Qualcomm.  Any ideas?

[hambone625]

I too am interested in this I got a RAZR m from a coworker that had a stock nonroot phone that he ota'd to 4.4 and said it went wonky now all I get is the green led...

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[RikRong]

If you have the green light, that means you're getting a charge. Can you boot into fast boot?

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[hambone625]

Can't boot into anything.. From what I was reading the green led only indicates a power source not that the phones actually taking a charge

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