Originally Posted by ti-triodes
It's in an open rack with lots of air. Agreed it sounds like something is overheating. I'll probably open the cover and do a touch test after unplugging it and letting the caps discharge.
Take the player to another room, attach ONLY the power cable, and play something like a CD on Repeat All for a few hours. Any odor? (There will of course be no audio or video output since nothing else is cabled.)
I'm guessing the answer will be no.
Assuming it passes that test, and given that OPPO stated they found no problems, the most likely explanations are:
1) The odor is coming from something else in your setup. Not the OPPO. OR,
2) Something you have connected to the OPPO is faulty and is causing excessive draw against the power supply in the OPPO. Thus excessive heat.
I'm betting (2) will be the case.
There are several possibilities here:
1) You have a shorted cable attached to the OPPO.
2) You have a shorted device at the other end of some cable.
3) You are trying to draw too much power from the USB sockets by attaching USB drives that need a lot of juice and are not connected to external power.
4) You have a mistake in your cabling which is causing unintended power flow. As just an example of this, suppose you have two devices that want to share the Subwoofer. One common mistake is to wire both of them to the Subwoofer by using a Y-adapter at the Subwoofer so that the output signal from both devices can reach the single input of the Subwoofer. The PROBLEM with this is that those two outputs are not just connected to the Subwoofer, they are connected TO EACH OTHER. Which means you have the output of one device forcing voltage BACK INTO the output of the other device (and vice versa).
I used that last paragraph as just an example of the type of wiring mistakes we've had posted here. What you should do in YOUR case is carefully re-think your wiring looking for silly mistakes like this.
Here's another possibility: You have one heck of a Ground Loop current flowing. A Ground Loop is garbage current that flows along the cable shields of the cables connecting your devices trying to find a path back to Ground. The devices in the path don't even need to be turned on.
These days the most common source of such Ground Loop garbage current is the feed wire coming into your house for cable or satellite TV. I.e., that wire is not properly Grounded where it enters your house.
Another possibility is that you have a faulty device which is leaking wall power to its chassis -- and thus to the shields of the cables. This is actually a dangerous situation. The usual suspects here would be power amps.
The OPPO has a 3-prong power plug, which is a typical path for such Ground Loop garbage current to flow. So the garbage current may be flowing around the chassis shield of the OPPO to Ground through that 3rd prong.
A Ground Loop would typically have other symptoms, such as Hum from your Subwoofer, or horizontal interference lines appearing on your TV screen. If you have either of those symptoms, then you may have a severe or even dangerous Ground Loop that needs to be fixed. I say severe because it is highly unusual for enough current to flow in a Ground Loop to heat things up. Start by disconnecting your TV feed where it comes out of the wall in your viewing room, and also unplug your amps. Run the OPPO for a while and see if the odor is gone.