20 Most Recent Sony SPP A700 Cordless Phone (SPP-A700) Questions & Answers

Check the phone cord. It may be loose or not getting a good enough connection. WIth phone on the charger, you can also unplug the power cord, turn on phone, put it back, and plug back in.
If this does not work, you may just need a replacement handset because the circuit may be bad in yours.

http://esupport.sony.com/US/perl/model-documents.pl?mdl=SPPA400

Instructions below show how to erase messages - do you know how the messages were actually erased, and if any were not in fact erased? https://docs.sony.com/release/tam100.pdf

For the base station set the ringer switch on the base from high to low. To turn it off select off. You can find that switch on the panel where the phone plugs into the wall on the far left. The handset is adjusted the same way on the leftside as you are looking at the phone.

Not possible.

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