While soldering the battery cable, the solder tip accidentally touched the two components above the postive pad, and left some solder on it. See the two images below. I tried to remove it using a solder wick, and while I managed to get some of it out, the reset doesn't want to completely rub off no matter how long I expose it to heat.


I tested it using USB, and everything works fine. However, I'm worried about what will happen once I connect it to a battery. Any suggestions?

Those resistors are shunted with that solder blob. You have to clean that. Clean your iron tip and try to "grab" that solder out. Have a bit of patience, you can clean it.

Be patient, get the soldering iron tip nice and hot, soldering wick can help a lot along with some flux.

I've managed to clean it some more on the top, but there is still some on the side. I haven't tried flux, so might be worth trying.

If you don't have flux sometimes it helps to add a little bit of solder even though you're trying to remove it. Particularly when the original solder is lead free, mixing in new solder will help make it flow easier. Make sure your tip is nice and clean and solder sticks nicely to the tip. If this isn't happening it's time to change the tip, if you don't everything will be more difficult. Quality solder (with lead and flux) and wick with rosin in it will make everything easier as well.

Looks like that's the positive side so that should be easier to cleanup than on the ground where your iron is put to the test if it's not high temp, high powered enough.

https://www.kester.com/products/product/...cored-wire

Failing that use a hobby knife to GENTLY cut between the resistors then check with a multimeter that they are not still bridged before adding power.

Be careful to not put heat on the resistors for a long time. They are so tiny that they can easily slide of the board. If that happens it's not hard to put them back, but if you're careful you're good. Use a clean pencil type tip if you have it and run it between the resistors like scraping. It seems better though.

Looking at a close up overhead shot of the Flywoo GN475EVO ESC board, both of those capacitors look to be soldered to the same copper plane on the board (both connected to the "+" pad), so if you managed to bridge solder between the same ends of them it won't matter because they are connected together via the circuit board anyway. The same applies to the other two resistors next to the "-" pad. Use a multimeter to do a continuity check on those other two to see if the ends are connected together via the board. If they are then so will the ones next to the "+" pad be too. In which case I would just leave that solder as-is with a bridge between them instead of risking damage to the board by you trying to rectify something that doesn't need to be.

Guys, thank you so much for all the suggestions. While I didn't manage to get it completely off, I've learned useful techniques from you all.

I spent last night trying to clean it some more, but without any luck. No matter how much or how long I apply the heat, the solder doesn't seem to flow. I took it today to a repair shop, and the electrician agreed that it was impossible to get it out. He asked for my permission to remove the capacitor to clean the bridge, and put it back, but I said I'll consider my other options first.

Now something that I was hesitant to point being new to all this, is what @SnowLeopardFPV pointed out. When I used continuity test on the negative capacitors I got solid beep, and I assumed that it is fine to have them accidentally bridged for the positive capacitors. Does this mean I'm fine leaving it like this?

(05-Jun-2021, 03:40 PM)m3sgal Wrote: Now something that I was hesitant to point being new to all this, is what @SnowLeopardFPV pointed out. When I used continuity test on the negative capacitors I got solid beep, and I assumed that it is fine to have them accidentally bridged for the positive capacitors. Does this mean I'm fine leaving it like this?

Yes, you will be fine to leave it like that. Board designers often use more than one capacitor in parallel to increase the filtering capacitance. The newer version of the same board has 3 capacitors on each side instead of 2.

Thank you SnowLeopardFPV!

Will have to connect everything first, but once I do, I'll make sure to use a smoke stopper, and I'll update with the result

Appreciate the help everyone

I've soldered everything today, and can confirm that it powers up just fine. Have to tune it and fly it when I get the chance. Will post about my build soon!

Thank you all for your help

Great news. Happy flying