Missing resistor/cap on 7-24v (input) buck regulator for VTX. What Value?

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bigjoncoop

Joined Feb 1, 2019
125
On my video transmitter for my fpv racing quadcopter there are two components missing right next to the voltage regulator circuit. I noticed that the video transmitter stopped working. I took a closer look and I noticed there were two components missing. the problem is, one of them I believe is the smallest SMD component size and the other one is one size bigger so they do not have any markings.

I was able to get it working because I noticed two other resistors/ capacitors we're touching directly underneath the missing two. one of them had came dislodged, so I repositioned it it was able to solder it back down. and now the video transmitter Powers up. if it wasn't a video transmitter on a quadcopter I would just leave it the way it is but since video quality is of the essence, I woud like to at least solder on some through-hole components to replace the missing ones in case not having them will affect video quality.

Anyone know what value cap / resistor should be there? or a safe value? or Just leave it?

if is not important i can just put some conformal coating over pads and maybe add a good sized low esr cap on the main input pads to try to help smooth it out

here is a photo of the two components that are missing on a good board. Here are all the specs I know

Brand: Akk FX3
5.8ghz video transmitter - 25mw-600mw
Input Voltage: 7-24v
offers a 5v output pad to power cmos camera(which i dont use)


In case it matters, that IC is labeled ACCH - (texas instuments definition) - accumulator high byte [ACCH] — The most significant bits stored in the accumulator (ACC). See also accumulator.


thanks
 

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