Yamaha CS80

I have just replaced my waveshape converter chips (IC9) on 2 of the M boards in Bank 2...I did this with 2 chips from spare CS60 boards I purchased.
I believed there was something amiss with the board mounted chips when I found that all waveforms at the Chips outputs, were containining floor noise and lacked low end...

I checked White noise through the filters and it is perfectly fine.

The Noise appears in the SIN wave, the Square Wave and the Sawtooth Wave, so it isnt just a problem in the VCF section....

I swapped again some OSC Chips(IC8) and it is the same results with a slightly different tuning....

I dont have access to a scope,

Does anyone have any Ideas of something simple on the M board itself that would cause this type of result?....or could this be something off on some other board that is causing this results and only on  these 2  ???

Thanks for any Help in Advance.....