[blewsmusic]

Hi, sorry this is my first time here and I hope that I can receive some help for this new issue. 

I've had the 566 for 2 years and it's been working great. The other day I was in the middle of a session and it started to make a whining noise up around 7k. The noise was coming from the unit itself in the room, not in the recording. The unit was still passing signal. Then a few days later the unit stopped passing signal all together. 

I couldn't figure out how add an audio file but here is a link to an audio file of what the whine sounds like if that is helpful.
https://drive.google.com/file/d/1eL3wYeyMbuOLKTa19iMw_YqnHfJ1msG0/view?usp=sharing 

I haven't run a ton of tests, should I start with the basic tests? Is this a somewhat normal problem? Any help would be great. Thanks. 

[JPK]

Yes, start with the voltages tests, the heater and the high voltage (steps 3 & 4).
You may have a failed DCDC converter. This happens when the temperature gets too hot in the module.