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No output in TX.

PostPosted: Mon Jun 15, 2015 4:00 pm
by therrick
hi all.

I have a Peaberry here that was sent to me for repair. Initially there were pads lifted and broken on the PSoC. I removed the PSoC to survey the damage and come up with a plan. I believe I was able to identify the problems. After replacing the PSoC, soldering in the PCM3060 and adding small wires to repair the pads for the gentleman I returned it to him to continue his build. He reported to me the receive section was working well when he completed it.

After completing the build the receive continued to work but he had no output in TX. He then returned it to me and I have been pulling my hair out since. I have been able to build another one and use it for comparison and what I get is no output on any of the VOUT pins nor the VCOM pin. I suspect there may still be something wrong with the traces around the PSoC. I just don't know what pin(s) the PSoC uses to communicate with the PCM3060 in transmit.

Hopefully someone can point me in the right direction as I would like to get this working for the gentleman and get it back to him.

Than you in advance.

Re: No output in TX.

PostPosted: Mon Jun 15, 2015 7:16 pm
by kz1x
The PCM3060 control signals are shown on page 3 of the V2 schematic.

See page 8 of the TI PCM3060 spec sheet for the pin I/O on that part.

Pin 5 is the audio bit clock for RX and pin 10 is the equivalent for TX, for example.

I'd look there first.
If the PSoC sends clock in TX (PSoC pin 4) but you don't get it on the 3060 (pin 10), then that's a problem, and so forth.

To be frank, an attempt to repair a PCB like this one, once the pads are damaged, is like neurosurgery.
If you're successful doing it, you're a truly gifted craftsman.

Steve KZ1X

Re: No output in TX.

PostPosted: Wed Jun 17, 2015 12:35 pm
by therrick
Thanks Steve. I will look in to that. Yes this has been a challenge. I am hoping to get this fixed for this gentleman as I hate to see him lose the 150 for the Peaberry. Also it is such a nice radio for the price he should enjoy it.

Re: No output in TX.

PostPosted: Wed Jun 24, 2015 9:17 pm
by AE9RB
therrick wrote:I get is no output on any of the VOUT pins nor the VCOM pin.


No output on VCOM may mean the voltage divider in the PCM3060 is blown.