The Karbonn K140 is a low‑cost Android smartphone that originally shipped with the . Enthusiasts often replace the POP ROM with a stock Android build or a custom ROM to gain better performance, newer Android versions, and access to Google Play services. The “flash file” refers to the packaged firmware image (usually a .zip or .tar archive) that can be installed via a flashing tool.
If after flashing your phone still shows "IMEI null", follow this: karbonn k140 pop flash file