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Thread: Bad part can come from anywhere

  1. #1
    Forum Veteran WOPL Sniffer's Avatar
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    Screw it

    Bad part can come from anywhere

    I have to thank Lee, Glen,Joe and Don for assisting me with a problem which made me think I was a rookie...... I ordered the parts to build 5 DCP I had sitting here and after receiving all the parts from Mouser about 2 weeks ago, I started soldering them together. When finished, I installed a DCP in a fresh 700B WOPL I had just finished and when I applied power, there was no DELAY, the relays on the DCP immediately clicked in (think turn on thump).....

    So, I monkeyed around and had to take the remaining transistors, still in the original packing and do some measurements... They didn't measure up.... I get an OPEN reading between the base and emitter even when forward biased...... Just because you got new parts, does NOT mean they will work.... Apparently......



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    I had the nations problems figured out one night while on blah blah blah........ huh?

    Big amps
    Kenner Close N Play

  2. #2
    Forum Veteran Skratch's Avatar
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    Life is short, so take your time
    I have had the same problem from Mouser, I had 1 ohm and 10 Ohm in the same bag and they were the same banding
    I used to get lost in the shuffle, now I shuffle amongst the lost

  3. #3
    Forum Veteran WOPL Sniffer's Avatar
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    Screw it
    Well, Joe figured it out. They have the alternate TO-92 pinout that switches the Emitter Base Collector pin out. Even though the bag says "On Semi", Joe says they are Fairchild and

    "The pinout on the devices you got was E-C-B which is a commonly used alternate pinout for TO-92 transistors (to E-B-C which is more standard). If you swizzle the pin orientation, then things will work.

    well, ya lern something new every day... The data sheet didn't show that the pins were "swizzled" and if they had, I may have figured this out a week or so ago...... I'm going to swizzle this one for MY amp and try it. I'll wait for the good ones to show up that I just ordered. There is a reason we pay a dollar for a good transistor and 4 cents for the shit.....




    HUH???????
    I had the nations problems figured out one night while on blah blah blah........ huh?

    Big amps
    Kenner Close N Play

  4. #4
    Forum Veteran WOPL Sniffer's Avatar
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    Screw it
    after looking for the different pinout for the TO-92, I was unable to actually find it. Hmmmm
    I had the nations problems figured out one night while on blah blah blah........ huh?

    Big amps
    Kenner Close N Play

  5. #5
    Administrator Gepetto's Avatar
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    Quote Originally Posted by WOPL Sniffer View Post
    after looking for the different pinout for the TO-92, I was unable to actually find it. Hmmmm
    You won't find the alternate pinout for the 2N6517 Perry. Here is a TO-92 with the alternate pinout as an example.

    https://www.mouser.com/datasheet/2/115/APT27-464495.pdf


    The common pinouts for TO-92 are either EBC or ECB
    Last edited by Gepetto; 04-07-2018 at 12:27 PM.

  6. #6
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    Halfbiass...Electron Herder and Backass Woof
    PITA to reverse 2 outta 3 on a straight layout...
    taking something that's already good, and making it better...........and for the knowing smiles that cross their faces.......Nando-2011...

    "Silence cannot be Misquoted"--Lazarus Short-2012 "

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  7. #7
    Administrator Gepetto's Avatar
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    Quote Originally Posted by WOPL Sniffer View Post
    Well, Joe figured it out. They have the alternate TO-92 pinout that switches the Emitter Base Collector pin out. Even though the bag says "On Semi", Joe says they are Fairchild and

    "The pinout on the devices you got was E-C-B which is a commonly used alternate pinout for TO-92 transistors (to E-B-C which is more standard). If you swizzle the pin orientation, then things will work.

    well, ya lern something new every day... The data sheet didn't show that the pins were "swizzled" and if they had, I may have figured this out a week or so ago...... I'm going to swizzle this one for MY amp and try it. I'll wait for the good ones to show up that I just ordered. There is a reason we pay a dollar for a good transistor and 4 cents for the shit.....




    HUH???????
    When you see 512- in the beginning of the part number they are Fairchild
    When you see 863- in the beginning of the part number they are ON Semi

    ON Semi acquired Fairchild 2-3 years back and they are merging their part numbers. ON Semi end of life'd TO-92 transistors a couple years back when their packaging house decided they wanted to encapsulate higher value parts. ON Semi made the decision at that time to discontinue their TO-92 line up (which was really a shame).

    Fairchild still has TO-92 packaging capabilities and that will probably mean a re-emergence of the full ON Semi line up over time (speculation on my part). In the meantime, be careful on the 512 parts until the QC processes sort out.

    That is the back story.

  8. #8
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    ---
    Not quite exactly. I have run smack dab into this issue many many times.
    I have STOPPED using part numbers that can generate this confusion.
    Too darn many people on Karma got caught by it and sucked up my time troubleshooting...

    There are two variants of the transistor and THREE parts numbers from Fairchild / OnSemi stocked by Mouser.com
    512-2N6517TA

    512-2N6517BU


    512-2N6517CTA

    Downloading the datasheet DIRECTLY from mouser, I looked closely and the third line in the sheet said:
    Suffix “-C” means Center Collector (1. Emitter 2. Collector 3. Base)
    thus the 512-2n6517bu is an EBC layout transistor shipped loose (bu = bulk)
    and the 512-2n6517ta is an EBC layout transistor shipped on a "tape".
    while
    the 512-2n6517cta is an ECB layout transistor shipped on a "tape".
    ALL according to the data sheet I downloaded. The "default" layout specified by the sheet is EBC.



    The EBC is traditionally on "american" transistors i.e. 2n numbers, while the ECB is traditionally a "japanese" layout.
    whatever the history
    the part numbers DO correspond predictably with the data sheet.

    It could be WORSE!!! They could (and DO) on others!!) have gain (Hfe) codes before the packaging specification
    Last edited by markthefixer; 04-07-2018 at 05:05 AM.

  9. #9
    Administrator Gepetto's Avatar
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    Quote Originally Posted by markthefixer View Post
    Not quite exactly. I have run smack dab into this issue many many times.
    I have STOPPED using part numbers that can generate this confusion.
    Too darn many people on Karma got caught by it and sucked up my time troubleshooting...

    There are two variants of the transistor and THREE parts numbers from Fairchild / OnSemi stocked by Mouser.com
    512-2N6517TA

    512-2N6517BU


    512-2N6517CTA

    Downloading the datasheet DIRECTLY from mouser, I looked closely and the third line in the sheet said:


    thus the 512-2n6517bu is an EBC layout transistor shipped loose (bu = bulk)
    and the 512-2n6517ta is an EBC layout transistor shipped on a "tape".
    while
    the 512-2n6517cta is an ECB layout transistor shipped on a "tape".
    ALL according to the data sheet I downloaded. The "default" layout specified by the sheet is EBC.



    The EBC is traditionally on "american" transistors i.e. 2n numbers, while the ECB is traditionally a "japanese" layout.
    whatever the history
    the part numbers DO correspond predictably with the data sheet.

    It could be WORSE!!! They could (and DO) on others!!) have gain (Hfe) codes before the packaging specification
    And to add further to any confusion, ON only made the EBC configuration and seems they use the CTA suffix for formed (splayed leads) tape and reel, while Fairchild made both pin configurations and used the C to indicated the alternate pinout config.
    Last edited by Gepetto; 04-07-2018 at 12:28 PM.

  10. #10
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    Halfbiass...Electron Herder and Backass Woof
    Were the ECB configurations to replace the Japanese transistors , or are there design considerations for that pinout??
    taking something that's already good, and making it better...........and for the knowing smiles that cross their faces.......Nando-2011...

    "Silence cannot be Misquoted"--Lazarus Short-2012 "

    " I Just Collect Smiles Craig......Cheap Smiles!-----Fishoz-2017

    "anything can be done, it's finding the easiest way that's hard"-----Bobbysdad--2014

    " Synth percussion is deadly to children, house pets and shitty power supplies"---Stephen Evans 2014

    " You have not reached the point of diminishing returns, you've just ran out of money

    " The Pioneer U-24, unfortunately, is just too expensive and rare to find. That's why I have one."--Nando-2014

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