(tr)uSDX Forum

I've just got around to trying to resurrect a main board that I previously fried. I replaced the ATmega 328P, loaded bootloader and firmware all ok.
With a classic band RF board I'm getting CW TX as expected (around 3-5W on all band - efficiency tweaks still needed), but in SSB I get no audio - using internal or external mic. I replaced the internal mic just in case - no difference.
Strangely, I get no receive audio on internal speaker or external. However, I do hear sidetone on CW TX.

It feels like software/firmware to me.......any thoughts from the hive mind?
Thanks
Steve

Did you unplug Key/external mic, when trying internal mic ?
´cause once you put something in the mic socket, internal mic is disconnected....
You can also check wether the switch of your 3,5mm socket is broken....

73 Manuel; DL2MAN

Hi,
Yes - I also checked continuity right through to the processor or the capacitor before the processor.
I've now tested the main board with another RF board and the fault stays with the main board as expected.
I've reflowed all the processor pins as best I can - all check out continuity wise as far as I can test.
I've also reloaded bootloader and software.
It just seems very strange that I don't have SSB audio TX or any RX audio - but do have CW TX and sidetone.

Could it be due to a faulty/clone ATmega chip??

It's not crucial that I get this working, I do have 2 more (tr)usdxs, but I'd like to beat the challenge!

Hello Steve,

i think you are right, probably a fake chip without ADC....
If you can't hear anything from RX and no SSB in TX, eg. no SSB is calculated due to no audio signal input.
I would replace the Atmega328 from another supplier.... and check again to get it alive again

73 de Chris

Thanks Chris - that's pretty much the conclusion I was coming to. Next problem is where to source a genuine one! Especially that will ship to NZ.... The search begins!

73 Steve