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Need help to identify this zener diode

lockman

Oct 24, 2022
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I have a glass type zener, thru hole mounting that I am trying to get a replacement for. The only marking I can decipher are, 1, 6 -2, below are 5 T. Sorry I can't focus my camera to post pix. These markings I read via 8x glass. Any help would be appreciated.
 

kellys_eye

Jun 25, 2010
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Write the characters as they appear, no added commas or dashes etc (unless they are part of the code). Post a picture of the circuit board where it came from - you should be able to get that in focus!
 

lockman

Oct 24, 2022
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OK so it would be marked 1 6 -2 below that 5 T. FYI it was located at position ZD7, zeners ZD3 ( 1n4742) and ZD4 (1n4751) were removed to be replaced. other blank positions ZD1 & ZD2 are not used. This is from a Ryobi OP400 40volt battery charger.
 

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kellys_eye

Jun 25, 2010
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The diodes may not be the problem - C2 is clearly damaged (exploded) and needs to be changed.
 

lockman

Oct 24, 2022
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That's not the result of a filter cond. exploding that is glue that the mfg. placed on items all over the board. I am still trying to find someone who can answer the markings on the zener that I asked for originally. That's why I posted here.
 

Bluejets

Oct 5, 2014
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C2 and C20 look puffy to me........
perhaps a clear shot of the other side of the board would help as would the numbers from any switcher ic'c or mosfets.
 

lockman

Oct 24, 2022
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Here is flip side of board.
And believe me, it's glue that you are looking at not an exploded cond.
 

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Bluejets

Oct 5, 2014
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Perhaps it is glue.......what both of us were looking at is the puffy casing on C2........
Just no telling some people is there..
 

bertus

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Nov 8, 2019
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Hello,

I also see that C2 looks a bit bulged.
Have a look at this page for spotting bad caps:

Bertus
 

kellys_eye

Jun 25, 2010
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As above - my comment had nothing to do with the glue. I recognise a dud capacitor by years of experience and C2 is dud. This is a very common issue with SMPS's and nearly always the cause of non-working. In most cases it doesn't otherwise affect the remaining circuitry so you may be leading yourself down the wrong path by assuming the zeners are faulty. What test(s) have you made on them?
 

lockman

Oct 24, 2022
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OK, I will check and replace those caps mentioned but, I still have 3 zeners that are defective that started this post. Two I have info on and the third that I cannot decipher for a replacement part number. As you recall I said that the markings were 16-2 over 5T. I have included some pix's I managed to take to confirm those markings. So I still am looking for a replacement for that one. The first pix shows 16 over 5, the second shows 2 and the third T.
 

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Bluejets

Oct 5, 2014
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AS above #10.......what tests have you done on the 3 zeners to determine they are in fact faulty.
Cannot make out your photos as they are too blurry.
Did you look at them before /during or after posting..??

BTW...nothing comes up when Googling any of your number letter combinations with reference to zener diodes.
 

lockman

Oct 24, 2022
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Checked them with my diode checker on my digital meter. As for the pix, they are readable when I check them on this site.
 

Sunnysky

Jul 15, 2016
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The diode checker should read 0.6 and open in reverse zener being > 2V

If the battery cells are aged and mismatched >10% voltages or < 3V you have more problems to consider.
 

Bluejets

Oct 5, 2014
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Didn't say what the "results" of the diode check were although that would be only preliminary.
An actual zener test would be more conclusive.
Would be very suspicious of 1 zener going down let alone 3 with the properties of the C2 cap at hand.
Guessing in this instance, "decode" to mean gave up given the info received.
Who knows.......
 

Bluejets

Oct 5, 2014
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(You're) He's welcome........
Whoa....hope that's not pointed in my direction........:cool:............I thought the Op received good info......seems many need to keep findings in their own little safe deposit box.
That includes any info about tests done.
 

kellys_eye

Jun 25, 2010
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Whoa....hope that's not pointed in my direction........
'course not!

I detect some embarrassment from the OP at being pointed in the right direction rather than making incorrect assumptions and doubling down on them.
 
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