Identify Diode with color codes?

[gmc]

I'm busy looking into a switched mode power supply from the early 80's which has no schematic, and also no component references on the PCB.

I think this component is a diode. It measures 046V in diode mode with the negative on the orange side.

I've not seen a component like this before and guessing it's a diode. I've removed it from circuit and no other markings are on it - measures 0.46V in one direction, and nothing in the other.

Trying to understand if this is a diode and if so could it be a zener? Is is possible to identify more information for the color codes?

[Terry Bites]

0.46Vf would suggest a schottky
It a SOD-64 package

[gmc]

Thanks - I wondered what that package was.  You could be rigtht about it being a schottky. I"ve started tracing the circuit and it doesn't seem to be configured to a zener.

[Ian.M]

The cathode is the end with the colour band nearest to it, and often a wider band.  You read the color code starting from the cathode end so that is code '35'  Unfortunately that only gets you part of the part number, as you don't know what prefix letters or digits, or suffix letters are in it, or it *may* even be a 'house' code that has to be cross-referenced using the diode manufacturer's databook.

[EPAIII]

Perhaps I am crazy here, but if it is a diode and it reads 0.46V one way and open the other, then it would seem to be functioning properly. This suggests that it is not your problem. Move on.

On the other hand, if it is a zener, and you want to check it's zener Voltage, then take readings with the circuit powered up.

[gmc]

Forgot to add, this is not just to find a faulty component. I'm also trying to create a schematic from reverse engineering the PCB as no schemtic exists. I am trying to add in as many compnent values as possible.

SMPS is also dead, so troubleshooting as I go along.