Hello & Welcome to Just Answer,
I'm Greg and will do my best to assist you today.
Sorry to hear of any issue you are having with your phones.
To help you with this issue, may I ask:
1) The FULL Model Number of the phone system you are working with? Since this is a cordless system, that model should be printed on a sticker on the bottom or back of the MAIN base and START with KX-TG, and then be followed by a 4-digit number.
2) What phone service provider (phone company) you have for this phone line?
3) Is this the SAME system that "used to flash" - when a new message was left?
Please REPLY using the box below and the SEND button.
Very good - I'm glad you figured it out.
Please let us know if you have any more questions about your phone system.
Thanks, ***** *****