Why is volume disappearing?


My cj Premier 11A and ET3SE start up just fine.
After 5 minutes or so, the volume disappears. It's like some one is turning down the volume pot down.
All tubes have been replaced with NOS tubes from a trusted vendor.
Problem still exists.
After restarting the system the same problem come back.
Suggestions appreciated.
bogeybuster49
Metro04:
It happens instantly after approximately 5 minutes.
As for contacting CJ... I bought a new ET3SE/phono and took delivery two days before Christmas. I sent CJ an email January 2 regarding issues with the pre. I'm still waiting for a response. I sent another email last weekend about this issue and still haven't heard anything from CJ. Guess I won't be buying CJ again let alone recommending their products to anyone.
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