I’ve traced the problem of low LNB voltage that causes the S-9 to work for a while then drop off. There is a small part that looks like a disc capacitor near the tuner that actually is a PTC thermistor that goes bad.
This part provides short circuit protection, but when bad it trips off at loading well under the max rating of 500ma. The two bad ones I have found so far are marked M60 065.
On my own OpenBox that is still working, this part is larger and is marked JK60 065. Digi-Key engineer crossed this to a “Little Fuse” brand part # F1993CT-ND. It costs 58 cents!
This part can be changed from the top side of the board. Just snip the old one off.
Then tack solder the new one to the solder pads.
I then tested the S-9 by operating into a variable power resistor.
Ran it at 19v. @ 460ma. For two hours. The voltage and current held and the thermistor ran cool.
The S-10 uses the same part, M60 065, and is mounted on the tuner board. It has been confirmed that this Digi-Key part will fix the S-10 as well.