Unable to boot from an EFI SSD with Grub - internal drive now connected to USB
 

I had a setup of dual boot windows and Manjaro linux in EFI mod in my old laptop(with 2.5in SSD). Had Grub installed and everything was working fine till the laptop failed. Now I have got a different laptop (only m2 SSD slot) and would like to boot from the previous hard disk. I have bought a connector to use my SSD as an external one.
Once I connect the external disk and try to boot, it is taking me to grub rescue.
I have tried setting up the root and prefix to my / drive. But unable to find normal module while performing insmod.
How can I boot from the old SSD connected as external?

The 'different' laptop/motherboard you are now using knows nothing about your install so you need to reinstall Grub. First, is the 'different' laptop a new laptop or used and is it UEFI capable and does it have another hard drive and if so, is there any OS on it and what is it?. The link below discusses a situation similar to yours and there is an explanation/how to.

https://askubuntu.com/questions/8806...i-recover-grub

The laptop is new supports UEFI and have windows installed in UEFI. Thanks for sharing this. Will try the steps and see whether it works.

So you now have the new laptop with windows preinstalled and want to attach the old drive which has another instance of windows (?) as well as Manjaro. I'm not sure the windows from the old drive will work due to it being an external drive as well as new hardware but that old windows partition could be used for data.

If the steps in the link provided fail, post back with details on exactly what happens and any warning/error messages.

I am mostly interested in booting the Manjaro rather than the windows as it was my daily driver. I would like to get all my unsaved data including browser profiles, notebook sessions, etc. from Manjaro.
I have found a temporary workaround for booting from hard disk. I created another bootable Manjaro drive and used the search for EFI partitions in the Grub of the live disk.
It searched the external hard disk too and got me boot into the Manjaro installation.