Dead FC Review

Discussion in 'Build & Tune' started by BL Swagger, Apr 12, 2019.

  1. BL Swagger

    BL Swagger Well-Known Member

    I believe I have a dead FC, but wanted to run by my approach & findings with all of you to see if you have anything else to add.

    Starts off when I was attempting to install a Hellgate Buzzer onto an SPF3 FC. Things didn't go very well, and long story short, it ends with the quad not working anymore and the Hellgate Buzzer beeping loudly non-stop...

    I pulled out the multimeter and began to dig deeper. With the battery plugged in, I could initially see that the FC and Receiver were not getting any power. The PDB, 4in1 ESC, & VTX all received power.

    I began checking out the FC more and found that nothing was being outputted from the (+) pads. So since the receiver gets power from the FC, it makes sense that is off now too.

    But here is the kicker.. When plugged in w/ micro-usb to cleanflight, the signal wires output (1V) to the ESC's, which allow you to control the motors through Cleanflight. Still no power to the Receiver, so no remote use.

    So my conclusion would be that the power system onboard the FC is fried. I can see that the FC outputs signal, but not the 5V required to power itself or the Receiver.

    Does anyone have any additional thoughts on this? Im curious to see if its safe to say this FC is done.
  2. RENOV8R

    RENOV8R Well-Known Member

    Yep, you fried the 5v regulator by the sounds of it.
  3. SLFLY

    SLFLY Well-Known Member

    Yes a 5v regulator has fried. It's quite common on SPF3/Omnibus FC's

    If the fc is only powering via the usb socket, then the usb socket is the way to salvage it.

    Cut short a spare micro usb cable. Cut it about 10cm from the plug. Find the +/- wires on the cable, some times they are colour coded, look at a layout diagram of a micro usb socket.

    Fit a pdb board with a 5v output pad.

    Plug the short usb cable into the usb socket on the fc, and solder the +/- of the same cable to the 5v pads on the pdb. Then you have power!

    The receiver can also be powered from the 5v pads on the pdb. These pads are 2A so can cope fine.
    Last edited: Apr 13, 2019
    BL Swagger and Dugdog47 like this.
  4. BL Swagger

    BL Swagger Well-Known Member

    Funny, because I ordered a Omnibus F4 to replace it. Figured it would make for a quick replacement. Ill keep the SPF3 as a novelty for now and maybe use it for a spare build later on and rely on the PDB pads like you said.

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