At first glance, the MR3420 v5 looks identical to its predecessors. It retains the classic TP-Link aesthetic—unassuming, white, and practical. Under the hood, however, the v5 represents a subtle but significant evolution. With a capable CPU and double the flash storage of older versions (a critical factor for modders), it was built to handle TP-Link’s increasingly complex stock firmware.
But for the tinkerer, the "stock" experience is merely a starting point.
⚠️ Warning: Stock firmware disables USB tethering for some newer Android/iOS phones. If that happens, consider OpenWrt. tp-link mr3420 v5 firmware
| Build | Size | LuCI Web UI | Use case | |-------|------|-------------|----------| | Factory (from stock) | ~3.8 MB | No | First-time flash | | Sysupgrade (minimal) | ~3.9 MB | No | CLI-only | | Sysupgrade (with LuCI) | 4.2 MB | Yes | Too large – will brick |
✅ Correct approach: Flash factory → install luci and luci-theme-bootstrap to external USB storage (extroot). At first glance, the MR3420 v5 looks identical
The real power of the TP-Link MR3420 v5 firmware emerges when you ditch the stock OS. OpenWrt (version 22.03 and later) officially supports the v5 under the target name ramips/mt76x8.
Why install OpenWrt?
Stock firmware is available from the TP-Link support site (usually under "Archer C20" or "TL-MR3420" region-specific pages). The file is typically a .bin file sized exactly 3,932,160 bytes or 3,932,256 bytes.
This tutorial covers finding, verifying, and safely updating the TL-MR3420 v5 firmware, plus recovery steps if an update fails. Follow steps exactly to reduce risk of bricking the device. ⚠️ Warning : Stock firmware disables USB tethering
Messing with TP-Link MR3420 v5 firmware can lead to a soft brick (blinking power LED, no response). Here is the recovery sequence.