CS-LIME-27 (LimeSDR XTRX v1.3) - Hardware defect detected, unable to start via mPCIe, request support

Projects LimeSDR
1

Hello MyriadRF Team,

We have encountered a hardware issue with our CS-LIME-27 (LimeSDR XTRX v1.3) module. During initial testing, we found the device cannot be used normally due to quality problems, and we are requesting your support to check and process a refund.

Below are the detailed diagnostic findings:

Issue Description:
We detected a defect during diagnostics of the LimeSDR XTRX v1.3 module.

  1. When connecting via USB:
    When the module is connected via USB, after IC28 (ideal diode simulator, MAX402000ANS+ in our revision), we see a voltage of 5V on the VCC_EXT line, while the nominal range is 3.3 - 5V.
    - The FPGA IC starts up, and the LED indicators work (LED2 is constantly on, LED1 cycles once per second).
    - We have not yet tested PC connection functionality in this state.

  2. When connecting via LimeFEA mPCIe v1 (built-in USB):
    When connected through the LimeFEA mPCIe adapter, 5V appears on the VCC3P3_MPCIE input line. Downstream of IC23 and IC24 (ideal diode sim

2

Hi,

It looks like your post is incomplete.

3

A defect detected during diagnostics of LimeSDR XTRX v1.3.
When connecting the module via USB on the input power line, after the IC28 ideal diode simulator (MAX402000ANS+ in our revision)
a voltage of 5V appears on the VCC_EXT line, when nominal range is 3.3 - 5V. The FPGA IC starts up, and indication works (LED2 is constantly on, LED1 cycles once per second).
Efficiency when connected to a PC has not been tested.
When connecting the module via the LimeFEA mPCIe v 1. built-in USB, voltage of 5 V appears on the VCC3P3_MPCIE input line. Further down the line are IC23 and IC24 ideal diode simulators (MAX402000ANS+ in our revision).
After this, approximately 2.5 V is present on the VCC_EXT line. As a result, the LP8758A1E0YFFR DC/DC converters cannot start, and the module lacks the main operating voltages on the power lines. The indication remains inactive.
Corresponding fragment of the power diagram is added in appendix.

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QQ图片20260428161837
QQ图片202604281618372161×1620 282 KB

5

Hello, is it still incomplete after I have answered my question? Please reply to me urgently. Thank you.

6

Hi,

Just trying to understand what may went wrong. One more request - could you please share picture of your setup. I.e. how everything is connected together.

7

For an initial functionality check, it’s enough to power the PCB using available power sources.

The PCB is powered via a USB adapter, a 5V, 1A power supply (Photo 1), or directly from USB (Photo 2).

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图片1
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图片2
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图片3
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Photo 2 shows that the LEDs on the PCB light up, indicating that there is supply voltage on the VCC5P0_USB line and, correspondingly, on the VCC_EXE line (Scheme 1). When power is applied to the adapter, voltage is present on the VCC3P3_MPCIE line, but not on the VCC_EXT line.

12

Thanks for update. It looks like IC23 and IC24 are damaged on your board.

13

Hello, what should I do with the damaged parts? Can I apply for a refund? Do I need to return them to Trade Ze? Please help me to answer, whether you can directly contact Trade Ze to handle the follow-up after-sales matters. Thank you.

If you need to return the parts to Trade Ze, what is the RMA processing flow of your company? Please help and answer. Thank you.