Hi Susan and welcome to JustAnswer,Thank you for the question and your patience. Should you still need assistance for information purposes only...Initially, will it work using a MONO earphone plugged into the MONIT (8Ω) jack?
To my recollection, this particular model has a built-in cut-off switch in the MONIT (8Ω) jack. Plugging in a fitting MONO earphone would then serve as both an attempt of a fix and as a test by process of elimination.
Would you be comfortable trying 'something' that would fit; say cotton bud ? The idea is to 'jar' the cut-off switch into action. This is the only easy user doable attempt as all others would be internal; a hardware issue.
Cotton buds or cotton swabs; Please click HERE.
To my recollection, yes; something like 3.5mm. But that would only be a test / try fix.
If not corrective, then an alternate approach to/for a player might be more to your advantage than internal repairs.
And a means of converting the contents of the microcassette to a digital / MP3 format that can be saved/played in a phone and computer.
Susan, any microcassette player would work with the tape inside this Panasonic. There are online offers for 'used' (but functional) comparable if not similar purpose player/recorder.
Please click HERE and HERE.
With the earphone jack working, then it could be used to connect to the LINE IN jack (blue) of a computer and record in real time the contents. This recording then can be saved as a .wav file or (converted) into an .MP3 file.
The end result would be a one (1) time use microcassette player, a 3.5-to-3.5 cable and a perpetual electronic copy of the tape's contents.