Apple Studio Display keeps draining power, even when blank and asleep
giuliomagnifico.blog
giuliomagnifico.blog
Its not immediately clear to me if the Apple Studio Display, or your hardware includes the same co-processor that other Apple Silicon now have.
You've pretty much ruled out what you can do in software. Next steps would probably be voiding the warranty, finding the offending circuit branches or probing with a logic analyzer.
If you have an SDR handy, you might be able to get more information from RF emissions. I remember a fairly recent -thon talk where SDR was used as a side channel for debugging hardware/software. Not finding the talk now, but there was a tutorial on doing something like that here (below). The talk I saw used a Kraken SDR array with some customization to isolate signals to those emitted by the circuits being examined. Was pretty cool, really wish I could find it now.
https://www.rtl-sdr.com/video-tutorial-on-debugging-rf-emiss...
The juice might not be worth the squeeze.
Yes, it could be, but actually the Mac goes back to sleep, it's just the display that continues to consume energy even though it's black! It seems more like an issue with the connection between the Mac and the Display.
Anyway I don't have the ability to debug the RF emissions, also because I don't know what I could see, it seems more like a firmware issue with the display to me.
I would imagine at a bare minimum the continual but stochastic presence of RF signals in certain frequency ranges, and at those ranges harmonics, might indicate computational activity as opposed to just a plain or stuck draw/sink.
Computation is usually fairly noisy, encryption moreso.
Non-linear junction detectors operate on that principle for detecting hidden audio bugs or cameras by passive listening, or actively by directed radio (looking for the characteristic reflections).
There are also some projects like DeepTempest that seek to actually reconstruct remote activity within a device based on RF emissions. A lot of insights though will depend on how well you know the hardware.
Anyway, this was just a thought. Too many mfg's today are doing stuff they shouldn't be doing with their equipment to the consumer's detriment. You really almost need to have an EE degree just to figure out what it is they are doing, or even know specifically what's happening in most cases.