I have seen and experimented with this phone as my friend has just purchased
one.  I don't know why it shorts out like that.  It just may be a setting
that got out of kilter.

But the manual for it is available in Braille by calling:

Verizon department for customers with disabilities 1-800-974-6006


It may take some perseverance to get it, but it is definitely available.

I hope you can get a replacement phone if necessary, because the 4500 has
now been replaced by the 4650, and it doesn't have as many speaking
functions as does the 4500.
Harvey