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Hot!part number of U7 in PICKIT 4

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kappa_am
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2021/01/11 18:35:54 (permalink)
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part number of U7 in PICKIT 4

Hi,
I got overvoltage in the circuit and blew up my pickit4. I opened it the U7, most probably it is a DC/DC converter, is damaged. I managed just read BZK9 on it. However, I think it is a marking, not a real part number. I would appreciate it if share with me the part number if it possible for you.
 
Thank you. 
post edited by kappa_am - 2021/01/11 21:29:06
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    dan1138
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    Re: part number of U7 in PICKIT 4 2021/01/11 22:58:34 (permalink)
    4.5 (2)
    kappa_am
    Hi,
    I got overvoltage in the circuit and blew up my pickit4. I opened it the U7, most probably it is a DC/DC converter, is damaged. I managed just read BZK9 on it. However, I think it is a marking, not a real part number. I would appreciate it if share with me the part number if it possible for you.
     
    Thank you.



    It is a Microchip part:
     
    https://www.microchip.com/wwwproducts/en/MCP1640
     
     

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    #2
    kappa_am
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    Re: part number of U7 in PICKIT 4 2021/01/12 17:16:59 (permalink)
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    Thank you. It was really helpful. What else do you think is damaged? This one was physically damaged but I am not sure about the rest of the components. The LED is purple but the PC and MPLAB do not recognize it. Lets change this one see what happens.
     
    Thanks again
    #3
    dan1138
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    Re: part number of U7 in PICKIT 4 2021/01/12 17:59:55 (permalink)
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    kappa_am
    ... What else do you think is damaged? ...

    I do not have a schematic for the PICkit4 so it is impossible to say.
     
    As you have observed physical damage to U7 and this part is a boost mode switching regulator almost every thing that is connected to the VIN supply pin of U7 is vulnerable to damage.
     
    Murphy's rule of thumb in these circumstances is that the most expensive and hardest to replace parts receive the most damage. :)
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    kappa_am
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    Re: part number of U7 in PICKIT 4 2021/01/12 18:28:16 (permalink)
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    You're right. One time I blew up Mikroprog programmer because of ground isolation failure. All components were ok except one with a damn QFN package! but I got it working. After that, it was easy to repair that.
    I ordered one, but I will try to repair it to see what can get damaged. 
    One more question, How did you manage to find the part from its marks? I know there are some search engines online, I tried them; useless!
     
    Thanks
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    dan1138
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    Re: part number of U7 in PICKIT 4 2021/01/13 00:29:36 (permalink)
    4.83 (6)
    kappa_am
    One more question, How did you manage to find the part from its marks?
    I know there are some search engines online, I tried them; useless!

    I would like to think I found it because I am just the smartest kid on the planet but we all know that ain't so. :)
     
    Like you I tried a few SMD search tools and got nowhere. Then I used some deductive reasoning.
     
    The PICkit4 is a Microchip designed device, Microchip makes switch mode power regulator chips. So accessed the DigiKey web site for Microchip, SMPS chips in SOT-6 packages and looked at data sheets until I found the one in the right kind of package with an SMD marking starting with BZ.
     
    Seems simple with this explanation doesn't it.
    post edited by dan1138 - 2021/01/13 21:59:13
    #6
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