Motorola Startac 7868 - simple problem?

I'm still using my old Startac, and it seems to be muting itself. Now
according to the manual:

http://www.cellphones.ca/upload/manu...la_st7868w.pdf

....the mute option is only for muting your voice, and you should still be
able to hear the other party.

What's happening to mine is I'll open the flip cover, press PWR, and enter
then number and SEND, and I can't hear the phone on the other end ring. The
phone will dial and the other party will hear -me-, but I can't hear them.
AFAIK, the PWR button is not damaged. Turning it on and off again doesn't
randomly allow me to hear the dialing or ringing

So I go through the menu options, even looking at the 'roadmap' (pg 091) in
the PDF, and can NOT find the 'MUTE ON/OFF' screen. I know I've seen it on
the phone window. In fact I can't get the FCN key and the 6 key shifted
function (mute) to do anything when the phone is on. I press it a couple
times and then a '6' appears. I thought I recalled a little icon or
something appear and toggle, but can't recall.

The picture in the PDF looks -exactly- like my phone and all the menu items
match in the roadmap.

At any rate after endless and frustrating cycling through the menus not
changing anything, that I'm aware, I'll try it again and this time I can
hear the phone ring - though not every time. Took me three tries and as far
as I can tell, changing nothing, I'll hear it ring when I call my home
phone.

My question is simply:

1. am I somehow unintentionally muting it, or hitting some button with my
finger (I open it very carefully touching nothing but the case).

or

2. is this phone just FUBAR?

I remember this happening when my wife used it, we'd call her at the store
and be talking and she'd keep saying 'hello hello'. Then she'd get home I'd
go through the menus and find the word MUTE ON and change it to MUTE OFF,
and it would work, iirc. It's been years. She and the daughter have the new
phone and dear old dad has to take the old one.

Maybe I have the wrong model number and mine has a 'Set Demonic Mute
Option', lol. Not sure how to determine my model #.

Thanks for any help. I figure it's a lost cause and I should get a new
phone. Despite being good with computers, learning cell phone menus just
make me want to use the sledghammer option at times. ;-D

-Badger