I fried something but don't know what

[spiruline]

Hello,
I was installing a video transmitter on a Phanton 2 with H3-2D gimbal. Everything worked well and got a video reception until I touch by mistake the video input wire of the video transmitter with the V+ (11 volts) wire of the same transmitter while it was powered. Now I don't get any video signal.
These are the wires I touch by mistake:

I am not sure what part I have friend:
- The video transmitter
- The Video-out in the GoPro3
- Something between the Gimbal and the video-out wire in the Phantom2

What do you think ?
Hopefully it is just the video transmitter which is a cheap $30 unit...

 

[JimM]

it may be a resistor on the central circuit board. Not easily replaceable. it may be easier to replace the board, which is about the same price

 

[JimM]

open your phantom and check the two surface mounted resistors by the ribbon cable for the tx video and power that goes under the ph2 with the gimbal cable. If one of those is fried. Thats your problem.

 

[spiruline]

Thanks Jim,
Can I check those resistors without desoldering from the board?
Which values should they read?

 

[JimM]

If you've fried them it will be obvious.. A burnt mess

 

[JimM]

They are very small surface mounted components so not easy to unsolder or replace (for me) so I don't know what values. I just replaced the entire board.

 

[OI Photography]

From your pic it looks like the wires you crossed were the power output from the transmitter (red wire) that's used to power a camera, and the video input for the transmitter (yellow). That would send power down the video input line, and I'm guessing that would probably result in a blown fuse or other component on the video Tx itself.

The instructions don't always make it clear for those units, but the red lead on the same cable as the video feed should be removed or taped off to avoid problems like this (and confusion with the red lead on the other plug that feeds power to the Tx), if you're not using an FPV camera that requires that power.

EDIT: looking again, it's possible that the same power surge was sent up the vid feed to the Phantom's board as well, so you should definitely check Jim's suggestion too.

 

[spiruline]

Everything looks clean on the main P2 board. So hopefully I won't have to replace that, which seem like a lot of work.

OI, yes, those are the wires I cross. Since the video input for the transmitter was connected to the video output of the P2, the damaging power could have gone both ways: towards the P2 and the V-TX. The V-TX doesn't seem very repairable so I guess I´ll replace the V-TX first and see if that works...

 

[JimM]

Thats good news.. you can check video output from the P2 before you order a new tx by connecting the video output to any device that has av input (tv, monitor etc)

 

[OI Photography]

Thats good news.. you can check video output from the P2 before you order a new tx by connecting the video output to any device that has av input (tv, monitor etc)

+1 that's exactly what I'd recommend to verify that it's the vtx that's dead.

 

[spiruline]

I have tried with another video input and the Video TX works. So next step is to check with a different GoPro to see if the video output of the camera works. If the problem is not in the camera it could be either in the gimbal part that picks up the video signal or in the main board :-(

 

[JimM]

Hmmm. the board will be the cheapest fix. Gopro or gimbal may be an expensive repair

 

[spiruline]

I checked with a friend's GoPro and everything worked well. So I fried the video-out in the GoPro :-(((

 

[JimM]

Sorry to hear that. Thats a shame. Does the GoPro function OK otherwise? Does it record to sd ok and do wifi and hdmi out work ok?

 

[spiruline]

Yes, everything seems to be working fine except the rear video output. The wifi feed does work. I haven't tried the HDMI, but it seems like the problem is only in the rear connection.
I was thinking about getting a new GP3+, but I am reading about all the far focusing issues and maybe is better to get another 3...