LimeSDR Mini - TX_2 -> LNA_W LimeQuickTest failure


Wonder if someone can assist.

I purchased a LimeSDR Mini from a local reseller and received it last week - in time for the holidays.
Earlier this week, I installed LimeSuiteGUI, LimeUtil and LimeQuickTest on an Ubuntu environment.

I first upgraded the firmware via LimeSuiteGUI->Modules->Program (Programming Mode = Automatic), which took me from 1.24 to 1.26.

Immediately after this, I ran the LimeQuickTest and discovered the problem as per the below.

---------- output -----------
LimeQuickTest --no-gui
->Start time: Mon Dec 17 21:58:10 2018

->Device: LimeSDR Mini, media=USB 3.0, module=FT601, addr=24607:1027, serial=1D3AD6D2C3638F
Serial Number: 1D3AD6D2C3638F

[ Clock Network Test ]
->REF clock test
Test results: 20372; 33569; 46766 - PASSED
->VCTCXO test
Results : 6711010 (min); 6711171 (max) - PASSED
->Clock Network Test PASSED

->Read data: 12 02 18 12 02 18 02

[ LMS7002M Test ]
->Perform Registers Test
->External Reset line test
Reg 0x20: Write value 0xFFFD, Read value 0xFFFD
Reg 0x20: value after reset 0x0FFFF
->LMS7002M Test PASSED

[ RF Loopback Test ]
->Configure LMS
->Run Tests (TX_2 -> LNA_W):
CH0 (SXR=1000.0MHz, SXT=1005.0MHz): Result:(-23.9 dBFS, 5.00 MHz) - FAILED
->Run Tests (TX_1 -> LNA_H):
CH0 (SXR=2100.0MHz, SXT=2105.0MHz): Result:(-13.5 dBFS, 5.00 MHz) - PASSED
->RF Loopback Test FAILED

=> Board tests FAILED <=

Elapsed time: 2.85 seconds

In exploring what could be the matter, I did experiment using LimeSuiteGUI as well as sdrangel.

I found that when transmitting a NFM signal in the amateur radio band on 145.500, when using an 'Antenna select" in sdrangel of the ‘Lo’ band [30M:1.9G], that the power output to the 1/4 wave vertical antenna is very low (I can only RX the signal on my HT radio when very close to the antenna (with max gain). Signal becomes scratchy at 3-4 meters and disappears very quickly thereafter). When using an ‘Antenna select’ of the ‘Hi’ band [2:2.6G] - the TX power seems much higher I only start losing the signal when much further away. Unfortunately I don’t have a power meter that works at these low levels…

The RX also seems a bit ‘deaf’. Right now I am able to receive FM broadcast radio stations OK, but still trying to find UHF or VHF analog TV signals, which come from the same towers. I will compare RX tomorrow against old RTL dongle. I have been using the ‘Wi’ setting. Using the ‘Hi’ setting the signals on the FM broadcast band is about 16dB lower.

Can someone confirm whether there is any possibility that some configuration parameter change made via LimeSuiteGUI could be causing LimeQuickTest to fail as per the above? I have scanned the source and it very much looks like LimeQuickTest does push a complete and full parameter configuration when it prints: “Configure LMS”.
If someone can confirm it would put my mind to rest that its the hardware and not something I may have messed up in the configuration.

I also managed to ‘roll-back’ the firmware to 1.24 by building LimeSuite 18.04.1 from source and then running “LimeUtil --update”. But LimeQuickTest still fails. So unlikely its a GW firmware issue.

(By the way, there seems to be some incompatibility building sdrangel using LimeSuite head and I had to go back to that older version)

Inspecting the unit - its a v1.1 and I can spot some components that don’t look positioned correctly and instead of snapping to the pad during the soldering process, seems to have snapped to each other. Tracing these specific ones on the circuit diagram, them touching seems OK and should not cause issues.

Thanks for the help.