Root can't turn on usb debugging to do a recovery because phone showing no OS installed

[shubham_l]

Hello guys I have Asus Zenfone 5.
I unlocked bootloader so I don't get OTA updates so I manually downloaded the firmware and installed twrp recovery to flash it.But while flashing it showed an error and got off.After rebooting the recovery shows no OS installed.
So I searched on net it said to install stock recovery and sideload firmware by adb so I manually installed fastboot,stock recovery but to flash the zip file via adb it shows error.But to do so usb debugging is to be turned on to use adb.
Please help me to turn on usb debugging without turning on the phone or please provide a procedure to flash a rom in fastboot mode..

 

[scary alien]

Welcome to our AndroidForums, @shubham_l.

First off, I don't have an Asus Zenfone 5, so my comments are generic in nature.

As I'm sure you're aware, adb does not work with/for fastboot/bootloader mode...

Also, except for the sideload option, adb does not communicate from the stock recovery (and even then, all you can do is the sideload function). USB debugging does NOT have to be pre-enabled--the stock recovery does NOT have any idea about your Android ROM's USB debugging settings--it's a whole different/separate bootable image.

To use the sideload option in adb, you'll, of course, have to have:

- a good USB cable (connected between your device and your PC)

- the properly installed USB drivers

- the device showing the stock recovery menu (to get there might be tricky...on my Nexus 5, I had to boot-up into the stock recovery menu first (easy), then the "dead Android" is displayed (i.e., he's on his back), then I had to press power and then the volume-up key; apparently other devices need volume-up key first and then power); anyway, when you get there you'll see something like this:

Android Recovery
<device name>
<version info>
user/release-keys
Use volume up/down and power.
Reboot system now
Reboot to bootloader
Apply update from adb
Apply update from SD card
Wipe data/factory reset
Wipe cache partition
Mount /system (not sure how/when this option is useful for...?)
View recovery logs (this is really, really cool/useful--will also show kmsg kernel logs! awesome )
Power off​

Anyway, not sure how much this helps in your case...I'm guessing/assuming that the stock OS/firmware you mentioned is available and flashable via the sideload feature--most times that's done via some other non-recovery flashing tool (fastboot flash, HTC RUU, Samsung Kies/Odin, etc...).

I'll also move your thread over to the root area for your device so that those most experienced can help you.

Cheers and best of luck!