what the heck part is this?

[hildy]

I've spent a good hour or two trying to figure out what part this is. Maybe you know? Markings look like

AJ
G3
519

What I do know: This is a diode from a Waldorf Blofeld. D8, to be specific. I believe it may be a zener. Have tried looking here for manufacturer markings, etc but so far, nothing:

https://www.theremino.com/wp-content/uploads/2012/02/ThereminoSystem_SmdCodes.pdf
https://electronics.stackexchange.c...components-or-how-do-i-identify-any-component
any ideas?

(edit: rotated image)

 

[mjrippe]

Well, I got this far: https://www.st.com/en/diodes-and-rectifiers.html
but no luck searching using those markings. Also, I think the "J" is a "U".

 

[Khron]

This is probably the most complete(?) SMD marking database i've come across so far:

http://chip.tomsk.ru/chip/chipdoc.nsf/vc1!readform&view=smd&cat=a&start=1&count=1000
That looks like a... SOD123 package, or perhaps SMA.

 

[Script]

There are more of those in the Blofeld? Could measure with DMM. Won't tell you what it is but give a hint.

 

[JohnRoberts]

with only two terminals there aren't that many choices.

A VOM can help reduce the number of possibilities.

JR

 

[mjrippe]

with only two terminals there aren't that many choices.

A VOM can help reduce the number of possibilities.

JR

Well, he knows it is a diode, and knows that it has failed. I don't think a VOM will tell him much more. Apparently Waldorf are not particularly helpful with out of warranty products either.

 

[Ike Zimbel]

Well, I got this far: https://www.st.com/en/diodes-and-rectifiers.html
but no luck searching using those markings. Also, I think the "J" is a "U".

Mike is correct that it is an STM part...

 

[Script]

Markings difficult to see/read on image.

Top left reads "47/" ?
Top right "G" ?

(What does it connect to (do) on the board -- top side / underside?)

Aside:
The Blofeld is a digital synth and sort of a specc'ed down rehash of the Microwave. It sold astonishingly cheap. So no exotic parts, I'd assume, and PCBs most likely made in China .

 

[31hz]

hi - i'll shoot you the part when i get to the shop Monday - it's been a few months since the last one I've done and i don't remember the exact value before morning coffee, but that is a known issue on those and were spec'd incorrectly.

 

[Script]

Cool. So what is it ? Let us know please.

 

[hildy]

Thanks all for the replies. I'll use the info given here and keep looking around.

One note: it's one of the first few components right off of the power supply.
I'd say it's a safe bet it's a shottkey. (my original guess was a zener, but Shottkey is almost a sure bet.) I've noticed a lot of modern gear uses shottkeys in this way.

The funny thing is, the unit powers up just fine without it. But my concern was that if it were a zener, which might possibly be helping regulate a lower supply rail (like a 3v3 thing for some control aspect of the unit), then leaving it out of the circuit could be a no-no.

 

[hildy]

Got word from on high:

"D8 is a P4SMA15CA... working as a fuse to protect the board."

TVS Diode. Makes sense.

 

[Script]

"D8 is a P4SMA15CA... working as a fuse to protect the board."

Thanks for letting us know. Love this place.