Phantom 3 Advanced Video Lag FIXED!

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So sometime around April 2016, I started to notice video lag, then turned into a bad 3 to 6 second lag with some drop outs. From what I noticed this started to happen after P3 Adv Firmware 1.8.80. I played around with downgrading, upgrading, sdcards, you name it. I figured I was stuck, then 1.9.60 firmware came out and I had hoped it would fix it.

Nope, no fix to the video lag issues I was having. After some time in the forums, no body seems to have a fix for this issue and nobody really seemed to understand what was going on. The only way I could get any kind of better performance was to switch from NTSC to Pal settings on the camera. Which would make the lag better 2 – 4 seconds. So I started to research some more. 

Some time ago, someone had posted in the forums that they had the same video lag issue, took it to a hobby shop and they fixed it, told him his gimbal board was dirty and fixed he was. I thought about that for a while and thought to myself BS, something else was going on. I’ve repaired countless gimbal boards, and I’ve never really had one that was “dirty” to the point in which it wouldn’t work anymore. Perhaps some dust, but nothing that I figured would cause the video lag issue.  I’ve got over 30 hours flight time on my P3 Adv with over 200 flights and not a spec of dirt in my gimbal.

So I started to trouble shoot this issue, because it was outside the scope of what I’d call “normal” problems. Sure people have tablet settings wrong, etc. But I knew this wasn’t that.

I did some tests flights and tried to log as much of what was going on as I could.

Cold Startup: No lag
10-30 seconds after power on: Lag begins
30-1min into flight: 3 – 6 second video lag

Every now and then it would stop lagging in flight for a short period (20-30secs). At this point I started thinking perhaps I just have a bad gimbal board, but I thought, no way, this thing has performed so well. Turns out, I was right. Something was going on.

I kept trying to feel the gimbal top plate after flights, trying to see if it was overheating. After all it performed well over the cooler months, now it’s summer and now I have this lag issue, I started to suspect this was some kind of heat issue.

Suspecting a heat issue, I tore down the gimbal completely and noticed something I hadn’t noticed before. There is some thermal pads on two of the 3 main chips on the gimbal board.

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These 2 chips had thermal pads, click for full size

 

On the left is the heat sink contact pads, there is a thermal pad between the chips and the heat sink pads. NOTE: Thermal paste will NOT work as the chip does not make contact with the gimbal plate.

There is an ARM2 Microcontroler on the upper side of the picture seen here…

Click for full size
Click for full size

What I hadn’t noticed before was that the ARM2 micro controller did NOT have a thermal pad, but did have a pad on the heat sink for it! I thought to myself is DJI nuts? No it doesn’t make a lot of heat, but it does make some. DJI at some point thought it needed to be cooled, but never added the thermal pad for it! Perhaps after testing in their climate they figured it didn’t really need it so skipped the 3rd pad! But down here is southern Texas, in 96F degrees this don’t work.

I’m not sure if this is how all are, but I’m assuming so. The thermal pad(s) that DJI used on the other two chips are low quality and I suspect after some time just don’t do the job of conducting heat.

So I jumped on Amazon and ordered some “BQLZR 15x15x1mm Soft Thermal Conductive Pads” link here, these little soft thermal conductive pads are good and cost $5.48! They are just the right size for the two larger chips, but 41v62F3MdDLthe smaller Arm2 MC I had to trim just a tad so that it fit right without blocking anything. Take your time here when placing the pads as fitment is important.

When you place the pads, place them on the heat sink not the chips themselves. I found it’s a lot easier to do it this way, then just flip the gimbal board over and place it down on to the heat sinks. Be careful with the motor flex cables they are all sensitive and easy to mess up. That flex cable is no fun to replace!

So after I put everything back together, I gotta say I was a little worried it wouldn’t do anything. I was really thinking from the forum posts DJI must of put out some bad gimbal boards in the Advanced. But I had some hope.

Got it all back together, grabbed a battery and powered up. 30 seconds pass, I’m flicking the camera up and down, no lag. I wait, 2 mins, no lag. I shut it down, take it out front and do a flight, no lag in 90F degree heat. PROBLEM SOLVED!

So guess I’m going to add this to my list of repair services as I know not everyone will want to do a gimbal tear down. But if you do here’s what ya need to do to fix your video lag issue. Perhaps next time I’ll do a gimbal tear down how to.

If you are having the 2 – 8 second video lag issue, and nothing has fixed it, I’ll be happy to do this repair for you, you can contact us here!
This repair would normally cost $60 plus shipping. There is however no way for me to say if your phantom 3 advanced is having this issue or not, however if you decide to ship us your phantom, we will troubleshoot it and find out if this is the issue or if something else is going on and speak with you before any work is done.

Brian Heckathorne
UAVDoc.com

 

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