Lexicon REFLEX noise problem

[jh]

Hi, 

I rarely do repair jobs, but I was asked to look at a Lexicon
REFLEX reverb today. 
Problem is a high noise floor on the reverb sound. (only on
reverb, not on dry signal). I checked the signals on all opamps
and the noise is equally there on inputs and outputs, so I doubt
it comes from a faulty opamp. One opamp has a discretized version
of the same noise signal, so my guess is that the noise comes 
from the digital or at least from the D/A conversion part. Or maybe
from the ADC even.
I have two questions:

(1) Does anybody know if this is a typical Lexicon or REFLEX problem,
     some component prone to failure ?

(2) Does anybody have schemos, preferably as GIF or other electronic
     format ? (Snail mail might come too late.)

Thanks in advance for every helpful hint,

JH.