Hans reminded me that there is another way to trigger the referenced message.
The first batch of Rev 1 QMX boards were soldered up at the manufacturer with a CS4334 chip mounted backwards. A massive rework effort at FDIM corrected that but it was later learned that a small number of escapes occurred.? You may wish to ensure that your boards are not bearing that problem.
The stereo ADC fails that I have seen have, so far, all been in conjunction with clearly observable component failures in the 5V smps.
On Wed, Jan 10, 2024, 11:03?PM John Z via <jdzbrozek=[email protected]> wrote:
Simon, Vlado,
The last time I saw this was in a post by David Walsh on 11-21-2023.
An over voltage on the 5V supply rail destroyed the analog front end of the stereo ADC chip. That chip is the most vulnerable of all that are connected to the 5V rail.
JZ KJ4A?
On Wed, Jan 10, 2024, 10:32?PM Vlado Karamitrov <vladn3cz@...> wrote:
Simon, I have exactly the same issue. Not sure if you were able to resolve your issue. I was about to post the following when I saw your message.
My situation is as follows:
Assembled the QMX (OCB ver 1.0) and did multiple checks on the board for any errors. I was able to upload firmware (Ver#1_00_014) although I had to use the jumper on the board to set the QMX in boot mode. It does come up but only up to a screen that says "Initializing: Audio System". At this point it appears to be "stuck" and won't respond to ON/OFF or any other control. Voltages appear to be correct as I do get the 5V and 3.3V coming out of the regulator boards. Not sure what to check/do next. Out of ideas at this point and any help would be highly appreciated.
