I have a Uniden phone that is FSK capable but the light never blinks when I have a voice mail. I have resetr the phone several times to no avail. Is this a Verizon thing or just a fault with my phone?
It could be a few things..
Visual Voicemail Indicator is an individual feature that needs to be present on your account and active in order for the signal to be sent to the phone. It's not an extra cost but it's not uncommon to just have Audible Indicator added as a feature.
Something somewhere on the line could be "scrambling" the FSK part - but this would also mess up other FSK signals like Caller ID.
It could be the phone.. if you know another line w/ a phone where it does work just swap your phone there and see if it works on your phone as well.