Screen went to hexidecimal and is locked

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Scott VO1DR
 

Posts: 3
Joined: 15 Aug 2022, 18:13

Screen went to hexidecimal and is locked

Post by Scott VO1DR »

Hi all, My first post. If this is addressed somewhere else, pls redirect me. Thanks.
I built my classic bands truSDX and overpowered it on 10 m (13.8V) and cooked the final FET. I replaced it and finished filter and power adjustments. I put it on the air about 3 nights ago and got my first QSO - dx from France with 3 W. Great! Soon after, the radio emitted a tone ~400 Hz on its own for 10 seconds and then screen went to a long hexidecimal string: 0E0F10111213151617. It was totally unresponsive to any controls. I cycled power and tried USB power - same thing. I have a photo, but couldn't figure out how to attach to this post (when I click image tab, I just get [img]).

Anyone know what happened? Any suggestions how to restore this to service? I'm hoping I don't have a "mini-brick"!
Many thanks in advance, and 72, Scott
dl6sez
 

Posts: 399
Joined: 30 Dec 2021, 22:54

Re: Screen went to hexidecimal and is locked

Post by dl6sez »

Hello OM,

you have to reprogram a firmware via usb with this serial showed on display.
Please have a look at the videos DL2MAN did for this topic and get the firmware on dl2man.de.

73 de Chris
Chris DL6SEZ, JN48XL near Ulm, Southern Germany
DL2MAN
 

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Joined: 30 Dec 2021, 19:18
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Re: Screen went to hexidecimal and is locked

Post by DL2MAN »

Scott VO1DR wrote: 05 May 2023, 22:42 anhexidecimal string: 0E0F10111213151617.
Hi,

This progression indicates a dead At mega.
I would suggest to re-install bootloader and burn fuses again. After that, try to reinstall firmware, but i have not too much hope and assume your atmega needs to be exchanged.
It can easily be done with hit air soldering equipment.

73 Manuel DL2MAN
Scott VO1DR
 

Posts: 3
Joined: 15 Aug 2022, 18:13

Re: Screen went to hexidecimal and is locked

Post by Scott VO1DR »

Hi Manuel, Thanks for info. I will try installing the bootloader and see if I can get my S/N to show up on display on startup. I have an Arduino Nano but not an Uno. Will a Nano board work for this? Also, if I need to replace with new ATmega328p, where is a recommended source for them and what are the steps to get the new one programmed from a cold start. I can solder on in, but I'm not an expert (at all) on programming with Arduino, etc.

Finally, any idea *why* this happened? Rig was working great and I had just made a DX contact when it gave a "death rattle" and went to that number on the display. I'd like to avoid that again!

Many thanks for advice. 72, Scott VO1DR
DL2MAN
 

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Re: Screen went to hexidecimal and is locked

Post by DL2MAN »

Hi,

Arduino Nano should work as well.
Instructions what to do regarding bootloader can be found here:
https://dl2man.de/3a-trusdx-bootloader/

Recommended source for AtMega would be any legit electronics supplier.
Chip crisis is over for the ATMega and they are available without problems:
https://www.mouser.de/ProductDetail/Mic ... GNmQ%3D%3D

Why this happened ?
No definate answer, but maybe common mode current in combination with heated up rig.
Aged microcontroller ? Seriously: I have no clue..... Sorry.

73 Manuel; DL2MAN
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nd6t
 

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Joined: 20 Oct 2022, 14:26

Re: Screen went to hexidecimal and is locked

Post by nd6t »

Problem resolved. Needed bootloader re-loaded, followed by complete firmware installation. Seems to work quite nicely now. After testing I returned it to Scott to see if he can get through another DX QSO without it mysteriously failing again!
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