No luck finding PWM - I looked at the boot messages and nothing stands out. The fan53555 is a PWM voltage regulator with lower output voltage.
Here are few other things that might be of use:
1) Setting HDMI resolution - on DHO800 line there is no direct menu item to set the resolution - for some reason my monitor got 1920x1200 and the output did not look right - here is a quick fix:
with a kbd connected: WinKey-N → Settings Gear Icon → Display → HDMI → Resolution → 1920×1080
Its possible to set the resolution using adb as well but the string has some magic numbers - after you set it using the above method you get find out what the value is:
adb shell 'getprop persist.sys.resolution.aux'
- use setprop to set the value
2) NFS mount - if one needs to move a lot of files or wants to save items directly on their NAS from the scope ( ie wave images, recordings, settings). One plus is that it does not impact the SD card and can increase its life ( doing the mount does not remove any of the existing files in /data/UserData ). I assume you have an nfs server on IP 1.2.3.4 running over TCP with version 4.2 and has an export disk /rigol:
adb shell
su -
busybox mount -t nfs -o proto=tcp,vers=4.2 1.2.3.4:/rigol /data/UserData
chmod a+rw /data/UserData
- the write speed is about 10MB/s based on my tests. Right now the mount does not persist over reboots - I may add some scripting to run at boot time, or you can have a script running from a remote host and perform the mount using adb shell su -c ... command.
3) Use busybox to find missing commands - I like less, so in the shell I can say alias less='busybox less' and now have a less command - to see all commands type busybox