[Elecraft] KDSP2 LED Stays On and No Audio

[Ed K]

My KDSP2 has operated very well over the past 2 years and four months since I built 
it... until last Saturday.   I had removed it to work on the front 
panel, installing indicator LEDs in the key caps as per the LA3ZA mod which went very well.   When I reassembled 
the rig to test out the mods the KDSP2 was not functioning properly.   
With the module removed and replaced with a unpcb bypass board, audio is 
restored.   I have made no changes to the DSP2 module and I do take the 
precaution of working with my grounded static drain mat and wrist band. 

The KDSP2 LED stays on instead of extinguishing after a few seconds which 
indicates that communication is down.   I verified that all connectors 
and pins are aligned properly and the battery measures 6 V.   With the KDSP2 installed, even though 
the LED stays on, I am able to cycle through the filters using the 
XFIL/AFIL Front Panel switch... but, no audio.

I seem to remember this problem coming up once but can't recall what to do to cure 
it... wish I had written it down when I had come across it before.   It 
seems that it is something simple that I am overlooking. 

I appeal to your collective wisdom in solving this problem... Thanks, 

Ed - AD7GR