One G1M Black Screen Issue Repair Report

By Nianfeng Li, WU6P

Mar 20, 2021

nian.wu6p@gmail.com

Abstract

   This report documents the process of fixing one Xiegu G1M amateur radio transceiver black screen issue, including the debugging process, root cause analysis and after-fact recommendations.

0. What is Xiegu G1M

  In short, it is a HF transceiver on Quad Band (80M, 40M, 20M, 15M amateur radio bands) portable SDR, on SSB/CW mode, running 5W QRP.

  1. The reported issue

   We have a fellow Ham reported:

   After using it (G1M) successfully for a QSO a few days ago, I turned the unit off to change the key and inadvertently installed the replacement key’s 3.5 mm plug into the adjacent socket for ‘Comm’ before I realized it and then installed the plug into the correct ‘Key’ socket. When I turned the unit on all I could hear was what sounded like a relay. The OLED did not display and there was no reception or transmit. 

2. Inspect the received Radio

  Radio looks decent from outside.

  Setup a bench power supply, 13.8V with 500mA constant current limit. Connect the power, dummy load, key to the radio.

  Try a Radio power-on.

  Confirms:

  • Radio has a power on (relay) clicking sound
  • Black screen
  • No response on any pin input or key input
  • No static noise on speaker

        Power consumption is around 340mA.

      (in comparison, I have another working G1M consumes about 410mA in receive mode)

3. Debug process

     At this moment, the internal power regulator circuit area is the main suspect (due to black screen and no response).  Of course, all options are open.

      With ZERO information on the Xiegu G1M schematic, no service manual, all debugging work needs to be performed on the spot.

Open the Radio case.  (Note, you can just un-screw the bottom 2 screws in front panel, and top 2 screws on the back panel, to open the case).

Visual inspection:

    No burn marks.

    No fuse found.

    A few “suspicious” marks on tiny components, to be further inspected later.

    A dent in the ribbon connector that can (very less likely, but can) potentially break the power connection, to be further inspected later. All connectors themselves are secure.

    Power input connector and Power-on switch are on different PCBs and only ribbon cable connections between them (so power must be delivered through ribbon cable).

    Ribbon pins are tiny. Hard to probe on.

   Multi-meter inspection:

        .13.8V input voltage is presented.

        . Follow the trace, the power diode is fine.

       . Down the line, the 7809 and 7805 power regulators presented.   Confirms that Power-on bottom controls the voltage on-off. When on, the related +9V and +5V represented.

       . Checked the tip/ring voltage on the “COMM” port, both measured 3.3V.  This indicates it is very unlikely the power circuit has issue.

      . Checked the “KEY” port, zero volts on the tip/ring. Strange. It should be pulled-up.

   As lacking documentation, and hard to trace the PCB, I went directly to CPU, STM32f405, find the chip pin out online, measure the VDD.  And Yes, 3.3V is there.

   Then went to the front panel Pin input area, and yes, confirmed 3.3V pin voltage is there.

   So Power is NOT the issue.

4. Debug process Continued

   At this moment, it turns out the issue is not a simple one, and it looks like the CPU can be dead, or firmware busted. I am looking at my oscilloscope, maybe check the clock signal first?

   But wait, did I think of the firmware?  Let us try that route first.

   It is fortunate (or say unfortunate to me at before?) that I have some experience on the G1M firmware update.  Itself can be written a separate report. 

   Hint: You need to reference the G90 firmware update document to guide yourself update your G1M firmware, and you really need to investigate the DETAILS.

   So, PC, USB, COMM ports, power-on. And I see the serial ports works (good sign).

So I do a firmware update (to latest version, v1.07 as of the report).

   Reboot the Radio, and everything back to life.  WaLaa ..

5. Root cause analysis

   But what happened?  Is the firmware just crashed randomly, or the mis-place Key into COMM port caused this (hard to believe, right?), or we have other hidden issue here?

   Let us look into the COMM port pin definition (through plug side, did I say we do not have much document before?):

        At the measurement shows, the tip and ring of this socket are both hot (3.3V in operation), so signal is active-low.

        If a key/paddle stays in the COMM port, the Paddle Dah is pushed, then the RXD is pulled to GND.

        And in straight key case, many straight key’s configuration is the ring directly connects to base/ground.   It sends LOW to CPU RXD constantly.

And at the radio side, if you are familiar with its firmware update process, you will know that at power on, it gives you few seconds to pause the normal boot (by sending any character through serial port at power-on stage).  Then first option in the menu through serial port is firmware update, and if you choose so, before you can do anything else, the radio will wipe out its current firmware and then waiting for a file upload. There is not even an in-famous “Yes, I want perform this dangerous operation willing-fully” warning sign here.

6. Root cause Confirmation

   So the theory is there, is it truly the real case?  A key in COMM port, will wipe out the radio firmware?

   Well, there is a way to find out.   I insert my Bug connector (which tip/ring are tied tother at Bug key) into the “COMM” port, power on the radio.

   Guess what happened!  …  Fortunately, it is quite easy to re-update the firmware as I just did once not long ago.  The good thing is there is no real long-term damage to the radio I can think of, so it is a fun (and scary) practice.

   Why Radio treats LOW serial input as option-1 in this case, is beyond my knowledge and imagination.  There is more test can be done, but I am here just for the fun part, so …

7. After work

   There is really no alignment work to be performed.

   Connected the RF power meter, confirm the power output is good.

   Turn on another radio on table, listen to this radio’s tone (even 5W to a dummy load has enough leak RF power), confirm the frequency is good.

   Nothing special here, as the radio is reported working FB days before.

8. Words to Manufacturer (Xiegu)

   I have to say, although this case can be categorized as user error, but such a simple error (connect key-plug into the COMM port) can wipe out the whole radio firmware and leave a dead block on table, is quite unacceptable.

A firmware update to prevent this behavior should be marked a must-do.

9. Words to Users

   Well, how we prevent ourselves from the same mistake?

   Maybe block all non-common-used ports? Google “Anti-Dust Earphone Cap” can give you some idea.

    Knowing you can fix it after the fact, hopefully can also help you find peace in mind.

    A few add-on words … Do not let this discourage you from using the Xiegu G1M radio (or their other radios).  I like G1M. The Performance*Fun/Cost ratio is pretty good.

   Another side note, last year Xiegu quietly updated the G1M firmware to v1.07, which brings in a narrower CW filter besides the default one. Love that enhancement. Kudos to the Xiegu engineering team, job well done.  (Although, the fact, that firmware v1.07, still carries the v1.06 title in display, is a tell-tale sign of (lacking) quality control in company culture).

  Stay safe, enjoy QRP and do CW no matter what.

261 thoughts on “One G1M Black Screen Issue Repair Report

  1. Pingback: meritroyalbet
  2. Pingback: meritroyalbet
  3. Pingback: madridbet
  4. Pingback: meritroyalbet
  5. Pingback: grandpashabet
  6. Pingback: child porn
  7. Pingback: child porn
  8. Pingback: fuck google
  9. Pingback: bahis siteleri
  10. Pingback: 1artificer
  11. Pingback: A片
  12. Pingback: Lincoln Georgis
  13. Pingback: sex
  14. Pingback: Arie Baisch
  15. Pingback: madridbet
  16. Pingback: Cory Chase
  17. Pingback: Essay writer
  18. Pingback: sleep lotion
  19. Pingback: valentines gift
  20. Pingback: zinc sunscreen
  21. Pingback: moisturize foot
  22. Pingback: 3comedy
  23. Pingback: Click Here
  24. Pingback: Click Here
  25. Pingback: Click Here
  26. Pingback: Click Here
  27. Pingback: Click Here
  28. Pingback: Click Here
  29. Pingback: Click Here
  30. Pingback: Click Here
  31. Pingback: Click Here
  32. Pingback: Click Here
  33. Pingback: Click Here
  34. Pingback: Click Here
  35. Pingback: Click Here
  36. Pingback: Click Here
  37. Pingback: Click Here
  38. Pingback: Click Here
  39. Pingback: Click Here
  40. Pingback: Click Here
  41. Pingback: Click Here
  42. Pingback: Click Here
  43. Pingback: Click Here
  44. Pingback: Click Here
  45. Pingback: Click Here
  46. Pingback: Click Here
  47. Pingback: Click Here
  48. Pingback: spaceros
  49. Pingback: no code robotics
  50. Pingback: Click Here
  51. Pingback: Click Here
  52. Pingback: Click Here
  53. Pingback: Click Here
  54. Pingback: Click Here
  55. Pingback: Click Here
  56. Pingback: Click Here
  57. Pingback: Click Here
  58. Pingback: Click Here
  59. Pingback: Click Here
  60. Pingback: Click Here
  61. Pingback: Click Here
  62. Pingback: Click Here
  63. Pingback: Click Here
  64. Pingback: Click Here
  65. Pingback: Click Here
  66. Pingback: Click Here
  67. Pingback: Click Here
  68. Pingback: Click Here
  69. Pingback: Click Here
  70. Pingback: Click Here
  71. Pingback: Click Here
  72. Pingback: Click Here
  73. Pingback: Click Here
  74. Pingback: Click Here
  75. Pingback: Click Here
  76. Pingback: Click Here
  77. Pingback: Click Here
  78. Pingback: Click Here
  79. Pingback: Click Here
  80. Pingback: Click Here
  81. Pingback: Click Here
  82. Pingback: Click Here
  83. Pingback: Click Here
  84. Pingback: Click Here
  85. Pingback: Click Here
  86. Pingback: Click Here
  87. Pingback: Click Here
  88. Pingback: Click Here
  89. Pingback: Click Here
  90. Pingback: Click Here
  91. Pingback: Click Here
  92. Pingback: Click Here
  93. Pingback: Click Here
  94. Pingback: Click Here
  95. Pingback: Click Here
  96. Pingback: Click Here
  97. Pingback: Click Here
  98. Pingback: Click Here
  99. Pingback: realtor advertise
  100. Pingback: start a business
  101. Pingback: Google reviews
  102. Pingback: 2023 Books
  103. Pingback: cemetery
  104. Pingback: search dececased
  105. Pingback: find a grave
  106. Pingback: IRA Empire
  107. Pingback: porn
  108. Pingback: Chirurgie Tunisie
  109. Pingback: Chirurgie Tunisie
  110. Pingback: meritking
  111. Pingback: madridbet
  112. Pingback: madridbet
  113. Pingback: fue
  114. Pingback: future university
  115. Pingback: Higher education
  116. Pingback: GPA Calculation
  117. Pingback: Critical thinking
  118. Pingback: Economics
  119. Pingback: Social Activities
  120. Pingback: Rota evaporators
  121. Pingback: faculty of dental
  122. Pingback: meritking
  123. Pingback: Cooperation
  124. Pingback: MBA tuition fees
  125. Pingback: grandpashabet
  126. Pingback: meritking
  127. Pingback: meritking
  128. Pingback: madridbet
  129. Pingback: child porn
  130. Pingback: fuck google
  131. Pingback: Pharmacognos
  132. Pingback: meritking
  133. Pingback: grandpashabet
  134. Pingback: fue
  135. Pingback: meritking
  136. Pingback: meritking
  137. Pingback: meritking
  138. Pingback: Radiography
  139. Pingback: smart systems
  140. Pingback: Msc in dental
  141. Pingback: meritking
  142. Pingback: grandpashabet
  143. Pingback: izmir escort
  144. Pingback: sms onay
  145. Pingback: steroid satın al
  146. Pingback: fuck
  147. Pingback: ozempic fiyatı
  148. Pingback: fuck
  149. Pingback: steroid satın al
  150. Pingback: striscia led letto
  151. Pingback: porn
  152. Pingback: pull up

Comments are closed.