With SMD components, the code on the package might only mean something to the manufacturer.
I would replace it by use. You need to determine how much voltage it has to withstand, how much current it could be expected to pass, and what pins are actually used.
It is a Schottky diode, according to the schematic. You have shown a partial schematic, so what is the rest?
I saw a reference to a video game with this diode, but I can find no cross for it. Reportedly it fed a 3-terminal 5V regulator.
Schottky diodes are low-voltage, and often low-current. You could replace it with a standard or fast-recovery diode, if that is all you can find.
Thanks. Was wondering why I could not make a determination after a search. I did find an 80 page .pdf on the matter, but it was a lot of general (uncertain) references.
You found the device in question that is supplying a 7805 (5v regulator-removed and tested). Was trying to keep it simple by only showing the introduction of the circuitry as things get complex really fast with electronics and I am no EE. The component in question ("S1 R") has a 50% voltage drop even after other potential parasitic components, so I added the zener and the device worked fine. I wanted to add a Zener to allow current to back flow in the event of over voltage.
Based on the schematic, "S1 R"/D1 is pin 1 and pin 2 use only. C67 is not populated so that pin is not used and pin 3 terminates immediately at the PCB. I think you are correct again: Device requires a 10V 800mah power supply, so I think a SOT 89-2a-30V should satisfy a replacement. Sadly, I have other components that indicate similar internal structure, but I cannot ID them either based on the markings.
Saving that question for ON Semi....I await their response. Guessing the problem is package size and labeling for later identification.
Not sure why the manufacturer used this diode given the circuitry. Based on the schematic it is in and out. Need to see if the initial PCB release included C67 cap as an explanation. It is a revision 2 board. First attempt at cutting cost?