Need help with diode identification....urgent

Much more likely to be a 5.6V zener, and if glass (and small) more likely to be 500mW rated. (NB: zener power rating is important). Pictures, and/or an accurate but rough diagram of the surrounding circuit would help - maybe a lot.

Have you tried measuring them with a multimeter on 'diode test' range?

Having no schematic is an absolute killer. :(
 
Last edited:
I would love to, but sadly I am without a camera temporarily.

I can't stress enough the utility and usefulness of a digi-cam when working on just about anything technical. For instance: if you had used a digi-cam to do a survey of your unit before working on it and more pics as you worked on it, you wouldn't be in this situation right now.

As it is deciding where the zener goes is only a small part of the puzzle. It's orientation and the other diodes' orientation are another piece, and then, as you state, we have to find out just exactly what these parts are.

Also, I have to agree with sregor, my 56v guess was most likely wrong. 56v seems like a very high voltage for use in a pre-amp. As Hyperion guessed, 5.6v sounds much more likely. The thing is that there are usually some prefix letters in a zener string that help to identify the exact series/part. And the suffix number/letter usually identifies the tolerance class and where it falls. Such as +0/-0.5v or such. Often a zener will have a tolerance code that puts it's working range a little higher or lower than the nominal stated voltage point. This is important.

The 1000ohm pad that you found is most likely the anode pad for the zener. But that's only a guess without a schematic.

Cheers,
James
 
I can't stress enough the utility and usefulness of a digi-cam when working on just about anything technical. For instance: if you had used a digi-cam to do a survey of your unit before working on it and more pics as you worked on it, you wouldn't be in this situation right now.

As it is deciding where the zener goes is only a small part of the puzzle. It's orientation and the other diodes' orientation are another piece, and then, as you state, we have to find out just exactly what these parts are.

Also, I have to agree with sregor, my 56v guess was most likely wrong. 56v seems like a very high voltage for use in a pre-amp. As Hyperion guessed, 5.6v sounds much more likely. The thing is that there are usually some prefix letters in a zener string that help to identify the exact series/part. And the suffix number/letter usually identifies the tolerance class and where it falls. Such as +0/-0.5v or such. Often a zener will have a tolerance code that puts it's working range a little higher or lower than the nominal stated voltage point. This is important.

The 1000ohm pad that you found is most likely the anode pad for the zener. But that's only a guess without a schematic.

Cheers,
James
Working on the digi-cam. It wont take long. It would help with which diode goes where, but it wont help with finding the proper replacements which I still need. Orientation isn't the problem. The board screening tells me that part.

The good news is that I now have a lead on a manual. It is on paper and has to come in the mail, hopefully it is complete and in good shape. We will see.
 
Moving along....

The service manual is now in the house.

The diode that says Z56 9D on it is given part number 02z5.6a

The diode that says T92 H9 on it is given part number 1s2092

Additionally I could use replacements for these diodes....

1s1553v

sel103s

02z24a

sirba20
 
02Z5.6A:
https://www.mouser.de/ProductDetail...Q8nqTKtFS/NTW9pm8IdF6oRYUp0hiVBv0mCnEc/lcfg==

1S2092:
http://www.datasheetcatalog.com/datasheets_pdf/1/S/2/0/1S2092.shtml
http://audiokarma.org/forums/index.php?threads/ca-810-diode-sub-help.630850/

1S1553V:
I can only find a datasheet cross ref to an NTE519, which NTE isn't a well respected brand here.
http://www.weisd.com/test/GenericParts_WEISD_view.php?editid1=1S1553V
A 1N4448 looks like a possibility (But I'd want a second+ opinion on that):
https://www.mouser.de/ProductDetail...MIjf2Iko6m3gIVB-R3Ch1LYAP0EAAYAiAAEgKyXvD_BwE

SEL103S:
Haven't found anything yet.

02Z24A:
http://pdf.datasheet.live/090c29fa/toshiba.co.jp/05Z51.pdf
If it's really only 250mW as the datasheet shows then perhaps:
https://www.mouser.de/ProductDetail...=sGAEpiMZZMtQ8nqTKtFS/FF/yV2TDb8zeatKAaCcJyo= (500mW)
If 1w:
https://www.mouser.de/ProductDetail...=sGAEpiMZZMtQ8nqTKtFS/JIts9HBLkA287lhf0lsY6U=

SIRBA20: (?20A Bridge Rectifier?)
Some info on the layout would be helpful. Inline leads? Square pattern? Distance between leads? 20A would seem like way to much for a pre-amp, so perhaps it's a 2A (would seem much more likely)?
http://audiokarma.org/forums/index....50mkii-help-in-identifying-some-parts.253346/

The above are just some guesses to start off with. It would be best for someone with more experience to step in and expand the search.

Cheers,
James
 
You could also try this:

Take your ohm meter and clamp one lead to the chassis. Test each of the 4 pads where the diodes were attached with the other lead. With a little luck only one of them will show something near to zero ohms. That would be the anode position for the zener.

Cheers,
James

Got them installed, turned out great.

By the way, you were spot on. The pad that had low resistance to ground relative to the other pads is indeed the pad for the zener.

Thanks again

Z
 
Back
Top Bottom