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

Thread Starter


Joined Feb 1, 2019
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.