The Only Purpose of this Post is to Help People Reflash Their Nexus 7 Tablets

(You probably don't want to read this unless you care about reflashing your 2012 Nexus 7 tablet from Android 5.0 (Lollipop) back to a release that make the tablet usable. After a few missteps I was able to reflash it, and the point of this post is for help others deal with the problems I had while reflashing on a single website, instead of the multiple ones I needed to solve the issues I had.)

(For those that care, you can ignore the below introduction and jump immediately to the issues this post is about.)

I have the first generation Google Nexus 7 tablets from 2012. It's major usage has been for reading email, using it as an Amazon Kindle reader, and my son's playing of Minecraft. It was an adequate tablet - until the Android OS upgrade.

It came in 2012 with Android 4.2 (Jellybean) and it worked fine. I upgraded to Android 4.3, and it worked fine. But when I upgraded it to Android 4.4 (KitKat) it started having trouble. It was sluggish in responding to user input, and it had trouble connecting to our WiFi router. It was so sluggish, that I rarely used it except for the Kindle app.

So, when Android 5.0 (Lollipop) came out, I was hoping Google had fixed all the problems in KitKat that made using the Nexus 7 painful.

It took months after 5.0's initial release before Google had 5.0 ready to install on the the 2012 Nexus 7. I had great hopes that 5.0 would fix all of the problems 4.4 had caused.

But 5.0 was even worse than 4.4. The tablet had become so sluggish it was unusable. Which meant it was time to reflash it back to the last OS version where the tablet was actually usable, 4.3.

Now to the hints to help other reflash their Nexus 7.

There are a number of guides on the web that give instructions and I'm not going to duplicate them. I mostly used this one.

Problem #1:

After running this command (you may choose to use a different .img file):
./fastboot flash bootloader bootloader-flo-flo-03.14.img

I would sometimes get this error message:

< waiting for device >

This is due to a bad USB connection. Try wiggling the USB connection on the tablet. Or try a different USB cable. Some websites said it could happen if you were using USB 3.0 (which my iMac doesn't have). If you get the < waiting for device > error message, just hit Control-C, fiddle with the USB connection and try again.

Problem #2:

While running this command to update the image (again, you may have a different zip file):

./fastboot -w update image-razor-jss15r.zip

You get these supposed error messages:

archive does not contain 'boot.sig'

archive does not contain 'recovery.sig'

archive does not contain 'system.sig'

These are not error messages! These messages are completely benign. Don't worry about them.

Problem #3:

After running the above ./fastboot -w update you get the message:

checking product...

FAILED

This means you tried to reflash your tablet with the wrong image. The first time I tried to reflash, I inadvertently downloaded the image for the 2013 Nexus 7. After I downloaded the correct 4.3 image and restarted the process, I successfully reflashed my tablet to 4.3.

And I really wish whoever wrote the fastboot code at Google realized:

1) Any message that is not an error should be clearly noted that it is not an error.

2) An error message should be absolutely clear what the problem is. Outputting just FAILED is not very helpful.