To whom it may concern,
First of all, thank you very much for issuing this PQR.
We investigated this case at MFTBC and confirmed that the failure ratio is not high. Therefore we consider that this is a rare case.
We would like to close this PQR once, and continue watch the field situation.
If you received similar failure report from the field frequently, please issue new PQR/QRS for all of the failed units. We will investigate the root cause of this case deeply as soon as receiving additional reports from your side.
Thank you very much for your cooperation in this case.
Best regards,