Thanks for contacting JustAnswer!I'm Seth, a technology expert with ten years of experience troubleshooting issues.
A quick clarification: When you say, "rebooted the system," can you tell me exactly what you did (e.g. what buttons you pressed, etc.)? The reason I ask is because... this is going to sound strange... not all things are always rebooted the same way, and I just want to be clear on the exact procedure you used.
Meanwhile, I'm looking up addit'l info to solve this issue for you!
Terry, two things stood out to me from your original description:
1a) "is *now letting through* pages" -- does that mean it wasn't before?
1b) and "flashing as if on hold" -- what happens when you pick the phone up and listen (or try to dial)?
You also said, "changed phones" -- what happens when you plug another phone into it? Does it exhibit the exact same symptoms?