LimeSDR Mini 2.0 - TX completely dead despite successful software execution

Projects LimeSDR
1

Hi everyone,

I am reaching out because I suspect a severe hardware failure on the TX chain of my LimeSDR Mini 2.0 (HW=7, GW=2.2, LimeSuite 23.11.0).

Symptoms and Diagnostics Performed:

  1. LimeQuickTest passes 100%, including the RF Loopback test.
  2. The RX chain works perfectly (verified by listening to FM via GQRX, the green RX LED operates normally).
  3. Under srsenb (compiled natively with MyriadRF API), the software starts and runs flawlessly without any errors. The PHY thread is active. However, the TX LED remains completely off, and absolutely no signal is emitted over the air.
  4. The Bypass Test: To completely rule out srsRAN, I used LimeSuiteGUI directly. I tuned SXT, powered up TRF (BAND2), and enabled a Continuous Wave via TxTSP (NCO).
  5. Result: Even with a direct command to the FPGA, the TX LED refuses to turn on, and no RF output is generated.

Since the software stack executes perfectly but the TX hardware remains physically unresponsive (while RX works fine), could you confirm if this is a known hardware defect with this board? Is there a specific low-level register write that can wake the TX amplifier, or another solution ?

Thank you for your time and support.