JYU Hornet S Drone - crashed board repair

[Doc38343]

JYU Hornet S Drone - crashed board repair

Have a drone board my customer tried to repair broken connector and burnt off 2 resistors and there is also a missing capacitor i suspect was knocked off in the crash. can't find any info on these boards but There are two one on each side. they have the same parts however I cannot identify the SMD capacitor value since it is missing and the one on the good board is in circuit. (i would rather not have to de-solder it) I also am puzzled by the resistor markings all are marked 01C but i noticed the values are different, some are 10K some are 5K and a couple are 1K, all marked the same. Any help appreciated.

Will include photos in a few min.

[Doc38343]

Re: JYU Hornet S Drone - crashed board repair

Here are a few pics of the board

[diif]

Re: JYU Hornet S Drone - crashed board repair

01C is a 10k 1% resistor. They are not all 01C, I see one marked 01A.
The only way to properly measure the capacitor is to remove it.

[R_J]

Re: JYU Hornet S Drone - crashed board repair

I did find this for the resistors, If you can identify the ic the cap. goes to you may be able to find a value on the pdf for it.
I think this is the 10 pin component, some esc use them, and are marked ADEF
If the missing cap connects to the BST pin it could be a .1 uf

[Doc38343]

Re: JYU Hornet S Drone - crashed board repair

01C is a 10k 1% resistor. They are not all 01C, I see one marked 01A.
The only way to properly measure the capacitor is to remove it.

Thanks brother I've been too busy today to work on this one but I was puzzled because a resistor marked 01C is reading only 4.9K so I think i need to replace a few of those. The owner tried to solder it and burned her pretty bad. I think it is salvageable though. On the cap thing i may just have to bite the bullet if R_J's suggestion doesn't help me.

I did find this for the resistors, If you can identify the ic the cap. goes to you may be able to find a value on the pdf for it.
I think this is the 10 pin component, some esc use them, and are marked ADEF
If the missing cap connects to the BST pin it could be a .1 uf

Thanks that chart is a huge help to me. I will try some thought and logic before I de-solder the other working board. That cap may not be too crucial of a tolerance. I think it is somewhat important the two boards work in harmony. I don't fly them i just repair the crash damage! LOL

Lesson in this: Find someone who can micro solder BEFORE you grab the old radio shack 50 watt...It will be cheaper!

[diif]

Re: JYU Hornet S Drone - crashed board repair

I was puzzled because a resistor marked 01C is reading only 4.9K so I think i need to replace a few of those.

The fact it's half of 10k suggests it could be in parallel.
If the two boards are identical, measuring the resistance on the other board should confirm this.

There is always this webpage too for resistor markings. (I'm too lazy for looking up codes in a list). It understands letters too. http://www.hobby-hour.com/electronics/smdcalc.php

[Doc38343]

Re: JYU Hornet S Drone - crashed board repair

I did find this for the resistors, If you can identify the ic the cap. goes to you may be able to find a value on the pdf for it.
I think this is the 10 pin component, some esc use them, and are marked ADEF
If the missing cap connects to the BST pin it could be a .1 uf

OK got a little time to examine and test and that cap connects to pin 3 and 5 of that IC. You are onto something I can see the markings under microscope and it is DEF 742 I did not see an A also didn't get any result on google.

It is a 10 pin and there are actually 2 of them.
Doing some more looking.

Thanks

[Doc38343]

Re: JYU Hornet S Drone - crashed board repair

GREAT NEWS!!
Thanks R_J you got me thinken on the right and I looked at the second IC and followed pins 3 and 5 and sure enough it went to the other side of the board and VIOLA there was the cap. I pulled it and tested and get 1.2uF (I will test again on my ESR tester I don't trust the Amprobe VM)
Still I am almost home on this puppy!

Got 1152 nF on my low value tester second test 1232 nF (hard to hold the tiny bugger on the pad)
Guess my Amprobe is more accurate than I thought! (good to know)

[R_J]

Re: JYU Hornet S Drone - crashed board repair

I thought the chips looked like the ones on this ESC module I think the `F' at the end can change, I have seen `E' and others, the 3 digit number I believe is the date code

[Doc38343]

Re: JYU Hornet S Drone - crashed board repair

You were right they are ADEF the numbers are all 742 but after i cleaned the flux better i could see the A I also noticed there are 6 total and all have the same cap going from pin 3 to 5 and following pin 5 out ward reveals it is much like the data sheet you attached. Thanks
I'm done for today but after i get the board traces repaired and components soldered I will post some more photos. I will see if the guy will do a test flight, I'm in downtown so he may not want to.

[Doc38343]

Re: JYU Hornet S Drone - crashed board repair

PROGRESS UPDATE:

OK I ordered some 603 assorted SMD caps and resistors as well as some 805 same.. They came today so here are a few progress photos.
This board is being repaired because the Drone owner cannot find where to buy just the boards. When he brought it in he had attempted to repair a broken connector with a radio shack soldering iron. (big) There was a meltdown and malfunction.... Photos speak for the rest. Note that i had already cleaned it a LOT when de-soldering the board for removal.

To the point now where I have to decide solder the wires or find the replacment for the burnt up jack. It looks like many I have problem is it is way smaller. I guess it is off to ebay or amazon again..... at least all the formerly missing parts are back.