Just hooked up DX-C390 and vocals are drowned out by instruments.

use warranty if as you say NEW

My dx-c390 is showing a "mech error" message, Onkyo DX ...

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Jul. 30, 2017 - My dx-c390 is showing a "mech error" message, Onkyo DX-C390 6 disc cd changer, just started today...the door - Answered by a verified ...

DX-C390 is displaying MECH ERROR? - Q&A - Best Buy

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Jul. 28, 2019 - DX-C390 is displaying MECH ERROR? - Learn about Onkyo - 6-Disc CD Player - Black with 2 Answers - Best Buy.

my onkyo dx-c390 6 disc player is giving a mech error ...

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Apr. 1, 2019 - my onkyo dx-c390 6 disc player is giving a mech error message. what ... Is there any error messages displayed on the display of the unit itself?

Both of the devices have optical connections, by getting a lead between the two you should hear the high quality sound from the unit. Make certain the optical connection is switched on and assigned to the Onkyo.
Only a record player requires a pre-amp. If it the amp doesn't have a dedicated socket for it.

No laser, means no laser. Typical symptom of laser failure. Most CD players can have the laser replaced fairly easily and cheaply.
Contact your local technician, and he should be able to replace it quickly.

Sometimes the tray ribbon goes bad causing bad connection to main board! Common
problem with alot of brands!

This is a comprehensive reference for disc players...


http://www.repairfaq.org/sam/cdfaq.htm

Hi,

You're tray may be opened with a belt, maybe it's slipping over the plastic wheel.

Good luck,
Gerard

no on/off switch on this model; use the remote or load it and press play AFTER you plug it in............

Use a surge protection power strip (such as the Power Protect AV 600 by Monster Power).

This will elliminate erratic behaviour of the unit, since even minute fluctuations in the power source from unbridled house current will affect the sensitive internal components of the Onkyo DX-C390 6-Disc CD Changer.