[TenTec] Ten-Tec 422 Amp Problem

[k0bx at arrl.net]

I hate to interrupt the forum with a real TT question, but here go's:

I have a 13 year old TT Centurion Amplifier which I have own for about 2 years.  I have it hooked up in break-in mode with my IC-756PRO3.  

The CW key the input  into the amp and the amp keys the rig.  There is a PTT line.
All has been working well until earlier this week.  The amp no longer keys the rig.  

The 'transmit' light flashes with the keying but doesn't key the rig.   
I tried the amp on SSB and RTTY and it works fine with full output.
I then unhooked the CW key from the amp and put it in the key jack in the back of the rig.
It works fine in semi-breaking mode.

The manual says the following:

I believe it is the QSK board but thought I would ask the group here before I order a new board.
Thank you,

Joe K0BX
Stop the insanity!

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