Hello & Welcome,
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? For a cordless system, that model should be printed on a sticker on the bottom or back of the main base unit and START with KX-TG.
I have a link to a video that is pretty good at explaining how to take one of these handsets apart & get it back together, which is usually the hardest part of this operation.
Click here --> https://www.youtube.com/watch?v=O4kwnaUaFMg
Please be CAREFUL/GENTLE when doing this job.
As for cleaning the keypad and surrounding "plastic", I usually remove the batteries from the handset, then use a bit of alcohol and either "drip & rub" the keys using a lint-free cloth OR I will "soak" the keypad for a few minutes, the push ALL the keys (especially the "sticky one") quite a bit - until the keys "loosen up"
Also, I have a link to Amazon where you can get a replacement handset - if that becomes needed. A replacement handset would have to be "registered" to the MAIN base unit before it would function correctly.
Click Here for listings --> http://amzn.to/29i0OsI
I hope this helps. Please let me know what you find or if you have any more questions.
Thanks, ***** *****
By the way, I have a link to another video from the same person that details how to CLEAN the keypad - once the unit is apart.
You may want to give it a look BEFORE attempting this operation.
NOTE: You may NOT need to get replacement keypads, as shown in the video.
Let me know if you have any more questions.
If this has answered your question(s), please take a moment to rate MY service level (Excellent is my goal) so that I get credit for helping you with this question.You should see some "stars" to do that, but please let me know if you do NOT see them (you may have to scroll UP or DOWN) or can not use them.
Thanks, ***** *****--. .-