Team,
Customer is observing a strange issue on the custom PCBs:
TAS5756M is used as I2S master and interfaced to an MCU (that decodes MP3 and output to I2S).
-At 44.1 ksps the system always work (whether or not it is mounted in the protecting case).
-At samples frequency < 24ks/s (typically 22.05ks/s) the system only works only if a small mechanical pressure is applied on the side of the PCB. This small pressure is seem to be as well applied when the board is in the case.
This problem is seen in appr. 15% of all the PCBs.
It does not seem to be a soldering issue (otherwise it would have the same behavior at 44kHz).
How can we debug further the issue?
I will provide the schematics/PCB (in PDF) off-line.
Thanks in advance,
A.