[TenTec] Paragon Problem Solving Info Needed

[Robert & Linda McGraw K4TAX]

With all the good technical folks here on the list I take the opportunity to get advice on resolving a problem with my old Paragon.  

Symptoms are:  
Receive on all bands and all modes is confirmed as OK.  
Press tune and it appears to switch modes, receiver mutes but after about 3 secs, S-meter appears to indicate signals from the input.  And there is no RF output while in tune regardless of the RF Power setting.  Pressing tune again does not return the unit to receive.  However, pressing LSB or USB does switch back to receive or changing the tuning knob will cause it to revert back to receive.   In transmit, via either PTT or VOX, there is no output when audio applied to the mike input however the unit does appear to switch into transmit, stays muted, but again after about 3 secs the S-meter indicates signals.  Again, releasing the PTT does not return the unit to receive but pressing  the LSB or USB (and maybe other buttons) will revert the unit to receive.

This unit has been sitting on the shelf for some time and has worked flawlessly on a regular basis.  Power supply is 13.8V and stable.  

Looks like something perhaps on the logic/processor board has gone west.  I haven't poked around inside thus thought I'd asked in the event someone else has experienced the same or like problem.  Any suggestions will be appreciated.

Thanks in advance.   Respond to the list or privately.  Either works for me.

73
Bob, K4TAX