Just to pass on in case anyone runs into a similar issue.

My 802 VLZ3 wouldn't power up properly. The level LEDs partly lit and it did not work. After a few moments a smell came from the power adapter.

Turns out there were two issues.
- one of the three wires in the plug that goes into the back of the mixer had a broken solder joint within the plug on the cord. The repair required disassembling the connector and resoldering. (It was the ground/neutral/common wire.)
- The power transformer inside the adapter "wart" had a "shorted" winding internally that resulted in heating of the core and very little output voltage. The repair required replacement of that transformer. I found one that was the same physical size and power rating at substantially lower cost than a replacement adapter and recycled the cords and case.

Note that other mixers in the VLZ series may use different adapters