Glass zener diode identification

I am working on a power supply and have found that a zener diode is bad, however I don’t know how to decode what type of diode it is. I think its either w15 or 315. I’ll include 2 photos of the device in question.

Hello Tech_Monkey,

I checked some Zener diodes in our system, and they do not have any information on the markings.
I would think it could be for a 15V zener, but we do not have one available in stock.
Maybe one of the engineers monitoring the TechForum can add to this, with any information to identify this diode.

This may be a silly question, but are there any of the same diodes that are legible on the board? Sometimes they may have this same part elsewhere on the board also. Other than that, it may be a 15v as David_1768 suggested possibly BZX79C15-ND; please review datasheet.

I have found other zener diodes on that board, but I don’t know if they are the same. This is the clearest photo that I could get. I’m not sure how to get a more legible photo if they are going to be marked the same way. Thanks for the help

Question for you when a zener is marked with 2 numbers is that always in reference to what reverse voltage it is? Thanks for your info on this part.

Markings on glass-body diodes of this sort tend to vary by manufacturer. A 15V zener might be a fair guess, but if a similarly-marked device can be found elsewhere in the device and its characteristics measured, that would offer a degree of confidence in the matter.

Failing that, I’d try to locate a schematic or set about reverse-engineering the device to identify a potential replacement. Note also that it’s quite typical for more than one component in a system to be damaged when things malfunction.

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I went ahead and replaced it with a 15V and that did the trick. I did use a huntron tracker 1000 to ensure that the signal looked just like the known good one and it did. After hooking it up and applying power I saw the correct voltages out of the power supply. Unfortunately there won’t be any schematics that the manufacture is going to share with us on this model or many others down the road. Thanks again for all your help, I’ll make note of the device for future reference.

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