Hello & Welcome to Just Answer,
I'm Greg and will do my best to assist you today.
Sorry I didn't see your question earlier and 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. (the KX-TGEA20 is the model of a cordless handset or charger)
2) How many TOTAL cordless handsets do you have with this system, and if more than one, are ALL handsets having the same symptom?
3) Is the ENTIRE display flashing, or just a few character/icons on the display?
Please REPLY using the box below and the SEND button.
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