Crown Studio Reference 1

Hi

Channel 2 of this amp is working fine, but channel 1 has no sound. The IOC (input output comparator) led is on. After a second I hear the relay turn ON, and the IOC led goes off. When the IOC led turns off the SIGNAL and ODEP green led turns ON. This is just for a second and the relay turns OFF again. This keeps repeating, the relay turning ON and OFF every second. I could not upload the schematic as it is 144 pages. I have checked all the components and they are OK, except the 2 ICs (C3381 and A1349). I think these are the preamp ICs. The manual indicates that the IOC led will turn ON if the signal overloads or clips. Any suggestions, please assist.

Thanks
 
I have checked all the components and they are OK, except the 2 ICs (C3381 and A1349). I think these are the preamp ICs. The manual indicates that the IOC led will turn ON if the signal overloads or clips.
Are you referring to U100 and U103? Please use Reference Designations rather than part types--- it was difficult to spot the devices you mentioned.

These two parts are associated with the protection network. It's possible they are part of the problem.

This is an amazing piece of equipment--- very complex. Do you have repair experience and test equipment?

Good luck!
 
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