A.research cd 3 mk2 doesn't work as a transport

I just bought an audio research cd 3 mk2 a used one -seems to be in perfect condition-plays ok like a CD player , but when I use it like a transport, stops and doesn't recognize the cd records.If anyone can give any idea? P.S The DAC works without it's own clock ,in a slave one mode.
Your CD player is fully balanced. You may have to do something to it in order to switch back and forth between bal and se operation. Your owners manual will definitely tell you what to do. Also, the problem may with not having the dac on the correct setting, either. The manual for the dac should cover this too.

It wouldn't hurt to check your digital cable, either. It may be damaged in some way.
Thank you Zd542 for your response.Finally I make it work tacking the signal before the pulse transformer and the IC of the Digital output! Have you any idea how I could take a I2S output Philips format from my player?