Newbie potentially fried a circuit on AKAI MPK25

Discussion in 'The Projects Forum' started by James Zoller, Mar 18, 2016.

  1. James Zoller

    Thread Starter New Member

    Mar 18, 2016
    3
    0
    So I picked up an AKAI MPK25 (a controller for music) and got a great deal because the usb was ripped out of it, but i was able to power it up and figured since I was starting soldering around the same time this would be a great test to repair and profit if I didn't really get into it as I have a number of other hobbies.

    So I ordered some type b usb female connectors to replace the broken one. I used flux because the type b usb has small holes that i was having trouble clearing out, but eventually got through it all and was able to mount (poorly) the usb to the board. In a rush of excitement plugged in the usb cable to the device and to my pc that powers it up without wiping or cleaning off the flux, and it worked for 10 seconds just fine, until it didn't. It still show signs that power is getting to it when plugged in, but it's not operating correctly, as if it it is only receiving a very small or minimal amount to show any activity and my computer does not recognize it. This happens when I use the power cable as well. So, it's worse off than when I started working on it today....

    Basically I want to know if I fried this thing or if I can somehow save this and have one successful project...

    It can be powered via usb or a 9v DC connection. Both of those power inputs show signs of life and I wasn't sure what was going on at first until i heard a sizzling sound and I have yet to plug it in since.

    I am new to all of this and view it as a valuable skill and fun hobby, but today has been nothing but failure on all 3 of my soldering projects sadly. So please help if you can, though I think I fucked this poor guy up...
    20160318_181921.jpg
    I have a:
    multimeter, 40w solder gun, lead solder, solder whisk, desolder pump, helping hands
    and a number of small tools/screws but nothing else really solder specific
     
  2. James Zoller

    Thread Starter New Member

    Mar 18, 2016
    3
    0
    EDIT

    I don't see an edit button, so I had a brainfart and said i used a 9v DC when I actually used the correct 6v DC to power her up.

    EDIT
     
  3. blocco a spirale

    AAC Fanatic!

    Jun 18, 2008
    1,438
    368
    Check your soldering.
     
  4. James Zoller

    Thread Starter New Member

    Mar 18, 2016
    3
    0
    I cleaned Q2 and C5 and desoldered part of the replacement usb and I think one of the pads are missing, though I don't know what a missing pad looks like relative to a burnt pad.

    Any assistance is greatly appreciated. 20160319_111749.jpg 20160319_112740.jpg
     
  5. Kermit2

    AAC Fanatic!

    Feb 5, 2010
    3,766
    928
    One leg on Q2 is not soldered.
     
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