LimeSDR Mini - Strange interference

Hello,

After about a year’s use, my LimeSDR Mini started to add some strange interference? to the incoming signal. It is also audible when listened to.
http://www.om3bc.com/LimeSDR/lime1.png
http://www.om3bc.com/LimeSDR/lime2.png
http://www.om3bc.com/LimeSDR/lime3.png
http://www.om3bc.com/LimeSDR/lime4.png
http://www.om3bc.com/LimeSDR/lime5.png
Tried also with SDRSharp and GNURadio, different SDRs, different USB connectors, USB cables and on two PCs. The same can be seen in every case where LimeSDR Mini was used.
Tried already to reset to default setting and updating GateWare with the provided Lime Suite, but did not help.

I used the SDR daily for receiving satelite telemetry data, but because of this error, the received data can’t be decoded anymore.

Did anybody else encountered this, is there a way to fix this issue?

Br, Joe, OM3BC

Hi @om3bc,

Test the board using LimeQuickTest and post log file here, please.

This is the log:
www.om3bc.com/LimeSDR/LimeSDR-Mini_1D40F74B21DAD0.log

[ TESTING STARTED ]
->Start time: Tue Dec 3 07:36:32 2019

->Device: LimeSDR Mini, media=USB 3, module=FT601, serial=1D40F74B21DAD0, index=0
Serial Number: 1D40F74B21DAD0

[ Clock Network Test ]
->REF clock test
Test results: 3705; 16902; 30099 - PASSED
->VCTCXO test
Results : 6710989 (min); 6711151 (max) - PASSED
->Clock Network Test PASSED

[ FPGA EEPROM Test ]
->Read EEPROM
->Read data: 12 06 1D 12 06 1D 02
->FPGA EEPROM Test PASSED

[ 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:(-25.6 dBFS, 5.00 MHz) - FAILED
->Run Tests (TX_1 -> LNA_H):
CH0 (SXR=2100.0MHz, SXT=2105.0MHz): Result:(-12.4 dBFS, 5.00 MHz) - PASSED
->RF Loopback Test FAILED

=> Board tests FAILED <=

Elapsed time: 3.65 seconds

[ TESTING STARTED ]
->Start time: Tue Dec 3 07:37:18 2019

->Device: LimeSDR Mini, media=USB 3, module=FT601, serial=1D40F74B21DAD0, index=0
Serial Number: 1D40F74B21DAD0

[ Clock Network Test ]
->REF clock test
Test results: 10160; 23357; 36554 - PASSED
->VCTCXO test
Results : 6711004 (min); 6711167 (max) - PASSED
->Clock Network Test PASSED

[ FPGA EEPROM Test ]
->Read EEPROM
->Read data: 12 06 1D 12 06 1D 02
->FPGA EEPROM Test PASSED

[ 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:(-15.1 dBFS, 5.00 MHz) - PASSED
->Run Tests (TX_1 -> LNA_H):
CH0 (SXR=2100.0MHz, SXT=2105.0MHz): Result:(-12.1 dBFS, 5.00 MHz) - PASSED
->RF Loopback Test PASSED

=> Board tests PASSED <=

Elapsed time: 3.62 seconds

Was there anything connected to the RF connectors when running LimeQuickTest? If yes, then disconnect and re-run the test.

In first half part of text is the test with nothing on RF connectors. Second half show test with RF shortcut on Tx and Rx connectors.