RF loopback test fails with "TuneVCO(CGEN) - failed to lock (cmphl!=3)"

Projects LimeSDR
1

Hi friends!

I recently purchased a LimeSDR mini. LimeQuickTest is failing with:

TuneVCO(CGEN) - failed to lock (cmphl!=3)
SetFrequencyCGEN(61.44 MHz) failed

Does anyone have any suggestions for how to troubleshoot this? If not, is the board itself potentially eligible for an RMA? (I purchased it on October 20.)

Here’s what I’ve tried so far:

  1. LimeUtil --update
  2. Installed a fresh copy of the OS with the latest packages from Lime Suite - Myriad-RF Wiki and retried the test
  3. I read LIMESDR USB RF Loopback Test FAILED - #2 by cmrincon - the test result is the same with antennae removed
  4. I read LimeSDR mini : RF loopback test FAILED! - #4 by mzs and Failing RF Loopback Test -Any Advice? - the device was disconnected for 24h & at room temperature prior to this test. The test also failed with chip temperature 15C.
  5. I read Lime SDR Mini RF Loopback Test Failed - no additional tests
  6. I read [SOLVED!] Read(64 bytes) failed TuneVCO(CGEN) - failed to lock (cmphl!=0) - the only power connection is USB3
  7. I read various other “TuneVCO(CGEN)” posts but none mentioned “cmphl!=3”

Here’s the full log:

$ sudo LimeQuickTest 
[ TESTING STARTED ]
->Start time: Tue Dec 24 18:16:45 2024
->LimeSuite version: 22.09.1+dfsg-1+b2

->Device: LimeSDR Mini, media=USB 3.0, module=FT601, addr=24607:1027, serial=1DA1467419856E, HW=7, GW=2.2
  Serial Number: 1DA1467419856E
 Chip temperature: 15 C

[ Clock Network Test ]
->REF clock test
  Test results: 41873; 44803; 47625 - PASSED
->VCTCXO test
  Results : 6710979 (min); 6711014 (max) - FAILED
  FAILED
->Clock Network Test FAILED

[ FPGA EEPROM Test ]
->Read EEPROM
Operation failed: error code 5
->FPGA EEPROM Test FAILED

[ 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
TuneVCO(CGEN) - failed to lock (cmphl!=3)
SetFrequencyCGEN(61.44 MHz) failed
TuneVCO(CGEN) - failed to lock (cmphl!=3)
SetFrequencyCGEN(122.88 MHz) failed
Failed to set sample rate
->RF Loopback Test FAILED

=> Board tests FAILED <=

Elapsed time: 1.08 seconds

Thank you,
Alex

2

Hi, I assume you have LimeSDR Mini v2, in that case your LimeSuite version is too old, it did not have support for the v2 board, so that’s why the test fails.
You should be using version at least 23.11.0

1 Like
3

Thank you for looking so quickly, especially on a holiday!

Hi, I assume you have LimeSDR Mini v2

You are correct! Sorry about that.

You should be using version at least 23.11.0

Great catch; you’re right! I attempted to add the myriadrf PPA but, because I was not on a supported OS version, the package manager fell back to the distribution version.

I built 23.11.0 from source, ran LimeUtil --update, and I’m still having the same issue. Do you know what else I might be doing wrong? Here’s the new output:

# LimeQuickTest 
[ TESTING STARTED ]
->Start time: Wed Jan  1 18:18:53 2025
->LimeSuite version: 23.11.0-gc2d9e877

->Device: LimeSDR Mini, media=USB 3.0, module=FT601, addr=24607:1027, serial=1DA1467419856E, HW=7, GW=2.2
  Serial Number: 1DA1467419856E
 Chip temperature: 23 C

[ Clock Network Test ]
->REF clock test
  Test results: 36136; 39066; 41889 - PASSED
->VCTCXO test
  Results : 6710989 (min); 6711024 (max) - PASSED
->Clock Network Test PASSED

[ FPGA EEPROM Test ]
->Read EEPROM
FPGA EEPROM not supported in v2
->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
TuneVCO(CGEN) - failed to lock (cmphl!=3)
SetFrequencyCGEN(61.44 MHz) failed
TuneVCO(CGEN) - failed to lock (cmphl!=3)
SetFrequencyCGEN(122.88 MHz) failed
Failed to set sample rate
->RF Loopback Test FAILED

=> Board tests FAILED <=

Elapsed time: 1.10 seconds

I also pasted the output of LimeUtil --timing at gist:0e8f4cb97f96bba1549c304e2a436d29 · GitHub in case it helps.

Thank you so much! I appreciate your assistance.

4

Were there any modifications done to the board? Are you using external reference clock?

Test log shows that the board is functioning, only the clock generator tuning is failing. That could happen if there would be a mismatch between what the software is expecting from reference clock (40MHz) and the actual board’s reference clock.

1 Like
5

I have not modified the board nor attached an external reference clock :frowning:

Thank you again for looking so quickly; I appreciate it!

6

@andrewback based on Ricard’s analysis, do you expect the 90-day board product warranty to apply here? (I am not using an external clock nor have I modified the board.) If so, is there a process that I should follow?

Thanks to both of you for taking a look!

All best,
Alex

7

@alambert yes, warranty should apply here.

@ricardas should we arrange an RMA or is there anything else you would like to try first?

1 Like
8

I think it should be RMA’d, in this case there’s nothing that software could do. The cause is most likely hardware related, but to verify it would require tools, I suspect something is wrong with the reference clock. The reference clock test only indicates that it is active, but cannot verify it’s actual value.

The only thing software could try here, would be to run a series of tunning attempts with different expected reference clocks and see it there is any change in tuning success, but that still wouldn’t make the board work as expected, because the actual clock value would be unknown.

9

Thanks for confirming.

@alambert will be in touch via email to arrange RMA.

10

That makes sense to me; thanks for the detailed explanation.

Great! Thank you @ricardas and @andrewback for your thorough investigation; I appreciate the time you have spent debugging my issue.

1 Like