2.Noise level of fan(model tgn354) is NC40. It exceeds the specification requirement of noise criteria NC35.
or Noise level of fan (model tgn354) is NC40 in compliance with the specification requirement of noise criteria NC50.
(I don't know if you are saying the noise level exceeds the criteria or complies with the criteria? Is the noise level criteria set at NC35 or NC50? In any case, make it 'the noise level" and 'the noise criteria'.)
3.However, the production of walkman (model upe290) had been ceased. New model catalogue has not yet been received and we estimate the delivery period is 1 weeks subject to final approval.
or However, Sony's industry has ceased manufacturing the walkman (model upe290). New model catalogue has not yet been received and we estimate the delivery period is 1 weeks subject to final approval.
However, production on the Sony walkman (model upe290) has been discontinued. A new model catalogue has not yet been received. We estimate the delivery period to be one week, subject to approval. (I don't really understand the meaning of this last sentence, though it is grammatically correct--for instance, what needs to be approved? And is the one-week period the time between ordering the catalogue and receiving the catalogue?)