ROCK 5B – solid green LED, no HDMI, no UART, not detected by rkdeveloptool

ROCK 5 Series 5B/5B+
1

Hi,

I have a ROCK 5B board that used to work fine (it booted Radxa’s official image from microSD with the same power supply).
Now it does not boot anymore and seems completely unresponsive.

Symptoms

  • Power LED is solid green as soon as I plug the power adapter, and it never starts blinking.

  • No HDMI output on any port, with a known‐good cable and monitor.

  • No Ethernet link LED.

  • The board does not appear as a Rockchip device over USB‑C when trying to use rkdeveloptool/RKDevTool (even when following the MaskROM procedure).

Power and boot media

  • Same power supply as when the board was working before.

  • Official ROCK 5B image re‑downloaded and re‑flashed on a microSD card (using Etcher).

  • Booting with only the microSD inserted (no NVMe, no USB devices) still results in solid green LED and no other activity.radxa+1

UART debug

I followed Radxa’s UART debug documentation (pins 8/10 on the 40‑pin header are TX/RX for the debug UART at 1500000 8N1).radxa+1

  • I connected GND + pin 8 (TX) + pin 10 (RX) to an ESP32 NodeMCU‑32S board acting as a USB‑UART bridge (GPIO16 = RX2, GPIO17 = TX2).

  • On the ESP32 I flashed a simple serial bridge sketch (Serial ↔ Serial2) and I can see the ESP32 boot log and a “Bridge ready” message on my PC serial terminal, so the bridge is working.

  • I tested both 1500000 baud and 115200 baud on ESP32 and on the PC side.

  • When I power on the ROCK 5B, nothing at all appears on the UART console: no BootROM, no U‑Boot, no kernel messages, at any baud rate.radxa+1

MaskROM / USB

I also tried to enter MaskROM mode following the Radxa documentation (hold MaskROM button while powering, connect USB‑C to PC, check with lsusb / RKDevTool). The board never shows up as a Rockchip device (no 0x2207:XXXX), so rkdeveloptool cannot see it.collabora+1

Question

Given that:

  • The board previously worked with this power supply and microSD.

  • There is now no HDMI, no Ethernet link, no UART output at all, even at 115200.

  • The board is not detected in MaskROM over USB‑C.

Is it reasonable to conclude that the board is hardware‑dead (SoC/PMIC/etc.) and should be replaced?
Is there any other low‑level test you recommend before I contact my seller for RMA?

Thanks in advance for your help.

2

I’m having the same issue on my rock 5b. I haven’t tried using rkdeveloptool yet tho. Have you gotten anything to work?

3

If the power LED is green and does not start blinking, it is most likely your power supply. The Rock 5B series of boards are very picky about the power supply being used. I have a simple usb-c power supply that works. Something like this: Raxda or UGreen - the UGreen works great for my board. You may need to fully clear and flash a new bootloader if this does not work.

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4

It might have been always an edge case, it only now causes a problem. Power supply can deteriorate. But it is an unspecified thing, so no-one knows and no-one can really help you.

For several ROCK5B in the field, 5V is not working. I have such a one, so I feed it with fixed 12V on the USB-C power input connector.

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