Newbie potentially fried a circuit on AKAI MPK25

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • cart
    Member
    • Mar 2016
    • 12
    • United States

    #1

    Newbie potentially fried a circuit on AKAI MPK25

    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...
    Attached Files
  • cart
    Member
    • Mar 2016
    • 12
    • United States

    #2
    Re: Newbie potentially fried a circuit on AKAI MPK25

    I mistyped when I said I used a 9v DC, I used the correct voltage of a 6v DC. Just so everything is clear.

    Comment

    • keeney123
      Lauren
      • Sep 2014
      • 2536
      • United States

      #3
      Re: Newbie potentially fried a circuit on AKAI MPK25

      It is best to perfect your soldering skills on on working boards that have been scraped.

      Comment

      • stj
        Great Sage 齊天大聖
        • Dec 2009
        • 30994
        • Albion

        #4
        Re: Newbie potentially fried a circuit on AKAI MPK25

        clean Q2 and C5 and get better foto's

        Comment

        • cart
          Member
          • Mar 2016
          • 12
          • United States

          #5
          Re: Newbie potentially fried a circuit on AKAI MPK25

          Originally posted by keeney123
          It is best to perfect your soldering skills on on working boards that have been scraped.
          well i suppose i am creating those scraped boards. home grown

          Originally posted by stj
          clean Q2 and C5 and get better foto's
          will do.

          thanks
          -cart

          Comment

          • cart
            Member
            • Mar 2016
            • 12
            • United States

            #6
            Re: Newbie potentially fried a circuit on AKAI MPK25

            Originally posted by stj
            clean Q2 and C5 and get better foto's
            Photos attached.

            Am I missing a pad?
            Do Q2 and C5 still look damaged?

            Thank you for any assistance.

            -Cart
            Attached Files

            Comment

            • stj
              Great Sage 齊天大聖
              • Dec 2009
              • 30994
              • Albion

              #7
              Re: Newbie potentially fried a circuit on AKAI MPK25

              the original foto's made them look burned!

              Comment

              • cart
                Member
                • Mar 2016
                • 12
                • United States

                #8
                Re: Newbie potentially fried a circuit on AKAI MPK25

                Originally posted by stj
                the original foto's made them look burned!
                something was wrong with them, and the solder was crispy. but i scrubbed them down with rubbing alc and they cleaned up nicely enough and the ICs seem undamaged. so that's good.

                question: That stuffed that looked burned was what was "sizzling" when i powered it on using either the usb or the 6v DC connection. should i attempt to power it on with the 6v DC connection to test that this can power on normally even if not by using the USB which was obviously my intent of this project? doesn't seem like i can do any further damage using the DC right now.

                q2: how do i deal with that missing pad so that i can do the original repair of adding a working usb connector?

                thank you for any assistance

                -Cart
                Last edited by cart; 03-19-2016, 12:20 PM.

                Comment

                • cart
                  Member
                  • Mar 2016
                  • 12
                  • United States

                  #9
                  Re: Newbie potentially fried a circuit on AKAI MPK25

                  The USB and DC power it up just fine and the usb won't be moving around anytime soon. Powered on via USB all night with various settings that would inform me if it shut down at all and it went just fine. It is fixed for all intensive purposes, and learned a lot along the way and still have a lot to learn ahead of me. The missing pad is a mounting pad and it is in their pretty firmly.
                  Wish I started this hobby/skill years ago.

                  These skills will certainly pay for themselves even if I just repair my own gear. One fixed laptop or DC connection and I've saved myself at minimum a $100 repair bill.

                  Great skills to have during this day and age.

                  Thanks again.
                  Attached Files

                  Comment

                  Related Topics

                  Collapse

                  • Astonished
                    Fixing the Charge Circuit of the Batteries of the DC Motor
                    by Astonished
                    Hi friends of electronics

                    What you see in the video and pictures attached is the circuit for charging the batteries of a DC motor.

                    The problem is that this circuit cannot charge the batteries (3 1800mAH NiMH batteries) any more. When the circuit was OK, its green LEDs lit up one at a time to show that the batteries have charged more. But now that the circuit is flawed, LEDs light up as you see in the video and at the same time successive beeps are heard.

                    Please help me fix this circuit.

                    (the datasheet of the IC: https://pdf.datasheet.live/28...
                    01-28-2025, 06:24 AM
                  • rddube
                    Lenovo L490 Ram voltage circuit malfunction
                    by rddube
                    Hello friends,

                    Looking for some guidance here. The RAM voltage circuit on this motherboard keeps burning out PU301 which is a RT8231AGQW. Copy of the board with the burnt chip attached with some voltage measurements and copy of the schematics also included.

                    I think I've checked almost every component in the circuit, but when I change the RT8231, the laptop starts I have 1.2V on the inductor for about 10 seconds and then the RT8231 goes south and no more voltage on the inductor. All other voltages on the laptop are good, this is the only one conking out for a reason I...
                    07-15-2025, 04:41 PM
                  • Tarot Superstars
                    Short Circuit tester
                    by Tarot Superstars
                    Hello.
                    I have seen a short circuit tester made with 3 * 9V batteries, a voltage limiter component and a resistor connected to the probes of a multimeter.
                    The theory is that the meter becomes sensitive enough to read very low resistances and the lowest resistance to ground on a circuit is likely to be a short circuit in that area.

                    Link
                    The Amazing $1 Short Finder Upgraded! Convert ... - YouTube
                    https://www.youtube.com/watch?v=0eixDdCpiO4

                    My multimeter isn't normally sensitive to very small resistance, but when I put a 1 mega ohm resistor...
                    09-25-2023, 09:11 AM
                  • M1NEBLANK SHOW
                    MSI B250 Gaming M3 Short circuit in CPU power supply circuit
                    by M1NEBLANK SHOW
                    Hello. MSI B250 Gaming M3 board, short-circuit on the power supply. Found a problematic mosfet VQ1
                    (N-PK616BA_PDFN8-HF) soldered it out - short circuit is gone. I replaced VQ1 + VQ5 (N-PK632BA_PDFN8-HF). VQ1 was replaced with PK618. After starting attempt VQ1 is lit again. What can be the problem? In the driver?

                    Schematic and Boardview here
                    ...
                    04-04-2025, 03:57 PM
                  • прямо
                    Viper22A 5VSB circuit
                    by прямо
                    So I have a cheap non working ATX PSU that I was learning to repair a decade ago. At the time, it blew the main fuse, bridger rectifier, NTC, and primary 9A 900V MOSFET. Replaced all except the MOSFET. 5VSB came back online. Then I poked around in it so much, measuring components one by one to a point I accidentally made the 5VSB circuit primary side went bang. Blown the AP8022 (Viper22A) PWM chip, along with a low resistance resistor and the PC817 opto isolator. I replaced them all.

                    In the process of poking around, I also lost a zener diode that stabilize the voltage coming from...
                    01-13-2024, 07:05 PM
                  • Loading...
                  • No more items.
                  Working...