Unit won't power up

[KA5ECX]

I had the unit stored for sometime but when I just tried to power it up from USB it did not start. I also tried using DC with the same result. I bought an assembled unit in 2022 or 2023 but I can't find when.
Thanks for any help.
p.s. As yet I have not opened the case.

[OK1ALN]

My radio also died recently during an FT8 broadcast and could no longer be turned on. The root-cause was improper/instable antenna connection thus high SWR while transmitting.

I'm not going to give you any sophisticated advice but I would start like this:
I would connect the radio to an external bench power supply or USB power meter and check the radio's power consumption as a first step. In my case the power consumption went into short circuit.

In the next step you can't avoid opening the device. Disconnect the control board and the board with the vf circuits. Repeat again the test with the power supply connected. This will verify which board is at fault. If your LCD power on then the control board is ok and you should look on the rf board. In my case, the power transistor has gone.

To verify this, I desoldered the L15 inductance and reconnected the boards, this isolated the shot-circuited PA transistor and was possible to turn on the radio again. So I have verified that it is defective and can order a replacement piece and replace it.

Do a basic diagnostic and post here where you got to.

[VA7BC]

Same issue here. I purchased an assembled unit in August 2022 from Sunny at NewDIYTech. Unit arrived with version 1.0 board. No problems with it until 2 days ago when it would not boot up. There is 12 VDC power detected at the pogo pins. No display and no sound. Emailed Sunny to see if they've had similar issues and could make a suggestion but crickets -- no response from her. So I guess I will purchase a new unit with the v1.2 board.....
73
Greg
VA7BC
Vancouver

[Luca66]

Same problem, but my main board unit only has a week of operation. I state that:
I left the firmware of Sunny version i
I have never used the unit with high swr, I use tuner.
I have not done power supply higher than 12.5 volts.
I tried a simple reset but it doesn't work
The drive is recognized ch340 when I connect the pc

I unfortunately suppose a quality problem in the central unit. There are too many cases that are emerging and Sunny has to give answers. I don't think that continuing to buy back ballots leads to a solution.

We hope Sunny reads these messages.
73

[Luca66]

I managed to wake up the transceiver.
I am writing this report to help others who may run into the same problem, describing how it happened and how I dealt with the problem without receiving any suggestions or advice. However, I would also like an opinion from Manuel or Guido on why the transceiver fell asleep and on the Avrdudess report.

How it happened
Main board new revision

Simply by removing the 12.7 volt power supply, unplugging the connector.
Reinserting the connector with the 12.7 volts already on the pin, the unit no longer turned on.

What did I do?

I consulted and wrote in the forum, but without getting any answers I thought it could not be a component failure but rather a freezing or complete reset of the ATMEGA unit.
So I reloaded in the following order

1. The Bootloader with AVRDUDESS 2.11.
The unit turned on
2. The firmware.

As you can see, the AVRDUDESS 2.11 software has finally generated a report that I would like to understand, I am not so competent to interpret it
Help me understand. Thanks.

[Luca66]

I thought I had solved it. Unfortunately not. The unit will turn off and not turn back on. I repeatedly reinstall the bootloader and firmware. But I'm amazed at how this forum doesn't work too..... But above all the official seller who is silent. Sorry but this is my opinion.

[Luca66]

I thought I had solved it. Unfortunately not. The unit will turn off and not turn back on. I repeatedly reinstall the bootloader and firmware. But I'm amazed at how this forum doesn't work too..... But above all the official seller who is silent. Sorry but this is my opinion.

Update, I reread an old post of mine that was about a bootloader loading problem with my first card. It happened that my card was faulty in usb communication. So I solved it by loading the bootloader and firmware via isp, the firmware in this case is a beta. I will try the same in this case too.

[pe1nnz]

When a (tr)usdx won't power up during/after normal use, the most likely cause is that the PA fets have been blown. These are then shortcutting the power-supply and then preventing the microcontroller to boot up or even impossible to reprogram. Power-up without RF board should be possible, and is a proof that something is wrong on the RF board. In such case replacing the bs170s is the best option.

Another unlikely cause could be that the microcontroller is damaged. In such case the microcontroller can or cannot power-up the radio and reprogramming fails or succeed but without the effect of storing the new firmware into flash. In such case replacing the atmega is the best option.

When a firmware update has been done, and the trusdx does not power-up, then either retry to perform the firmware upload via USB, or when this keeps failing, try to re-upload the boot firmware via ISP (Arduino or ISP device needed), instructions are on the website.

Does this help?

[Luca66]

Hallo Guido

I answer your suppositions.
The first is not possible because the fet of the classic board works perfectly. Separated the boards the mainboard did not turn on, while the rf board continued to work with another mainboard.
The third option is not possible because I had not updated the firmware.
The second instead could be plausible, because if you read my previous messages, the problem was not loading the bootloader but loading the firmware without errors and storing it.
So I tried to install the beta firmware with isp. And then I deduced that I had received a mainboard with a defect. For now it seems to work but I wait to shout victory. Unfortunately I regret the quality of the atmega components and I wonder if the official seller really makes a selection on the quality of the Atmega as I had read here on the forum. Otherwise what added value does the official seller give?
73

[pe1nnz]

Luca, thanks for the feedback and good to read your issue is resolved.

Indeed the whole idea of approved seller is that certain quality guarantees can be given for used components and compliance with the design idea. However that said, reliability issues still may happen in practice even for genuine components and the with best intentions of the sellers, and when they occur it's not always immediately clear what's causing them, it can be an indivual case, a bad batch or it may be caused by external factors like a design or use issue.

So when they happen, it's very valuable to analyse the fault in detail and circumstances in which they happened, so that a root cause potentially can be determined and the fault can be isolated. Only then it's possible to detect them in an early stage and/or to prevent them structurally.

[Luca66]

Hi Guido, yes the problem seems to be solved. I'm completely in accordance with your message.
In any case, the official seller should respond to requests for help also out of respect for your and Manuel's work. There is no doubt that no one will ever want to return a trusdx to China for a warranty repair, but we customers expect a form of assistance via email. Then we radio amateurs like to experiment and try to solve the problem by ourselves, but we are all the same. Together with the seller, we can find the solution to repair the product, Maybe I'm a utopian, but that's how I see it. I take this opportunity to ask you where we are with the improvement of the quality of SSB modulation and if it is possible that the type of rf board affects it, as I read on the forum. Thank you and 73

[pe1nnz]

Hi Luca, would be suprised if a response is left out from the seller, but note that right now whole China is on public holidays.

Indeed I worked last autumn on an experimental version with better SSB tx audio and IMD performance; there is still some work left to integrate this, and there is a space issue so if there is enough interest I probably consider a SSB-only release.

[pe1nnz]

Hi Luca, would be suprised if a response will be left out by the seller, but realize that right now all China is on the move for public holiday season. On the other hand you solved the issue so what's the point.

Indeed I worked last autumn on an experimental version with improved SSB performance; there are still integration and space issues to be resolved, and I might consider a SSB-only release if there is demand for it.

[Luca66]

Hi Guido, the problem is solved but my speech was in general In particular on the quality of the card. I bought a total of three main boards and three rf boards (one of each type). Two of the three mainboards are version 1.2 and have both failed, one of the two irretrievably. Will I be particularly unlucky or is it a quality issue? I'm glad to hear that you're working on ssb modulation. It is indispensable. Consider that I did some tests with a Spanish colleague alternating two trusdx
The first was a main board version 1.1 con firmware 'm' and low band rf. The second is Main board 1.2 with firmware 'x' and classic rf board. The frequency is 40m. The Spanish colleague, after comparing the two emissions, undoubtedly judged the first device, i.e. the one with the 'm' firmware, to be better. The device with firmware 'x' seemed to him to be affected by cmc. I would like to have the 'm' firmware To load into the mainboard r. 1.2 And do other tests. Where can I find the 'm' version for ISP upload? Thank you

[pe1nnz]

Hi Luca, is there anything we can learn from the two main-board failures, e.g. what exactly failed and what happened before the failure, how did you resolve it, can you show us a picture of the failed parts? The 2.00m version has the same modulation algorithm as 2.00i (the non-beta that is on the website).

[Luca66]

Hallo Guido, the photo in attachment are about the first main board. This main board come me with firmware 'i' and it kept working until I wanted to install firmware X and after trying it I wanted to go back to the original firmware.I wrote 'dead main board' post on April 4th in this section of the forum. This mainboard is not operative, I tried to install the bootloader and firmware via isp but it doesn't work.

[Luca66]

The second card that broke but that I have Saved It was blocked In the way I am described in this post. Later I upload the photos of the card. 73 and thank you

[pe1nnz]

Thanks Luca for posting the pictures of the first board. I have checked, the part looks genuine and part-number is not originating from a batch with known quality issues (that does not mean there could be).

Now since you report that ISP programming failures, here is what you could try (you have nothing to lose as the mainboard anyway is non-functioning right now):
1. remove temporarily C16 from the PCB,
2. put a dummy 3.5mm jack in mic, or if you do not have a jack, remove the onboard mic temporarily
3. remove the RF board,
4. add 12V power at the power jack before you start ISP programming. Then, try to re-upload the bootloader with correct fuse-settings. If this still fails, then read further as fuse-settings can be corrupt:

Wrong/corrupt fuse-settings can also be the cause of an unresponsive/bricked atmega chip, in that case you have two options:
5. unbrick it with a HV programmer or circuit [1]
6. replace it; even if you do not have special desoldering equipment, you can still replace it by adding a 2-3mm copper-wire around the pins of the chip and a lot of solder, at some after heating the part is displacable and you can move it off the pcb, then after cleaning wit solder-wick or copper-bread you can install a new part.

[1] https://www.instructables.com/HV-Rescue-Simple/

[Luca66]

Thank you Guido for your support. I'll try, I've got nothing to lose. 73

[Luca66]

Hallo Guido, This is the photo of the second main board.
73

Compress_20250505_064309_9534.jpg (173.31 KiB) Viewed 467 times

[VA7BC]

This is a follow up to my earlier post in this thread. My version 1.0 board (Lo band) was not longer powering up. It was a factory made (tr)uSDX by Sunny. Sunny did contact me and sent me a version 1.2 main board at no cost. Mail from China to Vancouver took only 12 days. Just installed it. It powered up nicely. I added beta firmware version R2.00x and calibrated the frequency. So far, so good. Kudos to Sunny for following up with me on this issue and resolving it.
73
Greg
VA7BC
Vancouver

[VE3RRD]

Indeed I worked last autumn on an experimental version with improved SSB performance; there are still integration and space issues to be resolved, and I might consider a SSB-only release if there is demand for it.

A SSB only version could become popular since it would also support most digital modes that use SSB. Maybe CW would be possible by using MCW with a tone centered in the narrow RX CW filter bandwidth.
AL - VE3RRD