# Help build the Qin F21 PRO Ultimate Guide

**URL:** <https://jtechforums.org/t/help-build-the-qin-f21-pro-ultimate-guide/5303>\
**Category:** Qin Phones\
**Tags:** qin-f21-pro, qin-phones, question\
**Created:** [December 22, 2025, 4:05am UTC](https://jtechforums.org/t/help-build-the-qin-f21-pro-ultimate-guide/5303 "2025-12-22T04:05:05Z")\
**Posts on this page:** 1\
**Showing post:** 64

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**Author:** ![ars18](https://jtechforums.org/user_avatar/jtechforums.org/ars18/32/11805_2.png) [@ars18](https://jtechforums.org/u/ars18)\
**Post date:** [March 27, 2026, 2:18pm UTC](https://jtechforums.org/t/help-build-the-qin-f21-pro-ultimate-guide/5303/64 "2026-03-27T14:18:03Z")

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I would just either pull your current firmware and resign it, then it can be flashed with spflash, or patch one of the older firmware like 1.0.8 to work with V2 and sign it.

Replace images in signed package and use original scatter.

Both guides available on the forum.

[https://jtechforums.org/t/guide-fix-new-batch-f21-pro-speaker-issue](https://jtechforums.org/t/guide-fix-new-batch-f21-pro-speaker-issue)

[https://jtechforums.org/t/lock-bootloader-with-custom-firmware](https://jtechforums.org/t/lock-bootloader-with-custom-firmware)

Then upload for ppl to use 🙂

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