Trying to understand why smoke comes out of my monitor.

[Neil H]

So I have been renovating some old Steadicams. These run off V mount batteries on the bottom brackets which feeds power to the camera and accessories on the top stage and the monitor on the bottom bracket.

Electrics is not something I know too much about but I’ve tried to do some research and taught myself to solder. I installed all the wiring and sockets and made up all the cables for the power and the video feed from the camera to the monitor and everything worked fine but my monitors SDI video input is broken. It’s a good monitor that would cost a lot of money to replace and the HDMI input works fine so I found a little SDI to HDMI converter. The converter though needs power too, 5V DC, and came with it’s own power cable that plugs into the wall. I plugged it in, fed the SDI video signal into the converter and then the HDMI out of the converter into the monitor. Plugged the monitor into the battery on the Steadicam and tested the signal. The converter worked great, no lag, good signal.


But obviously it’ll need to run off the steadicam battery too so I split the power cable coming from the battery to the monitor and put two DC plugs on it, one for the monitor and one for the SDI-HDMI converter and plugged them both in. I put the camera on the steadicam and plugged the video SDI into the converter and the HDMI from the converter into the monitor and before I could check for a signal smoke came out of the top of the monitor. I quickly unplugged everything.

I checked my monitor and it still works fine with the HDMI feed in but obviously I don’t want to plug everything back in as it was. What I was thinking was that there must be power coming down the HDMI and causing a short in the monitor. I checked all the cables again and they are all fine so I checked what was coming down the HDMI and it’s about 5V. I plugged the converter into the battery and the wall and checked both, they both have about 5V coming down the HDMI.

Do you think I’m right or have I missed something? I do need to put a boost buck on the power supply and I’m wondering if this would isolate the monitor/converter? Or will this set up never work without a separate battery for the converter. Or just biting the bullet for a new monitor. Any advice appreciated.

 

[telectrix]

is Sitting Bull or Geronimo residing in your monitor?

 

[shaun1]

How are you powering the SDI to HDMI converter? You mention (I think) that it came with a mains-5v PSU and requires 5v. You then say you split the cable from the V lock and powered it from here. Vlock batteries are normally 14.8v, are you converting this to 5v somehow?

 

[Wilko]

Hi Neil and Welcome to the Forum
Like Shaun, I think you have some mismatch in the power supplies. Be worth checking the polarity of them too. Perhaps try running the pieces separately and see they still work ok?
Apparently "letting the smoke out" is an activity that one gets used to with practice, I'm told

 

[ruston]

I would be wanting to see what damage that has done before I went any further.
I would not be happy waiting for the final outcome of melting something in there.

 

[Neil H]

No, for the tests they all had a regulated 12V supply from a V-mount battery plate. The Converter is 5-12V the monitor 12V. I did check the voltage coming down the HDMI with the converter plugged into the wall (5v supply) and plugged into the Battery (12v supply) to be sure and it was the same, about 5V.

I just took the monitor apart to see if I could find any damage and I found this chip with what looks like some kind of residue on the top. I could find no other damage anywhere and I smelt plastic burning so I’m thinking this must be it. I also found that this white connector you see highlighted in red on the left of the picture could have been pressed against the top of the chip. I can’t be sure. If this is the case it would be good news indeed, what do you guys think?

Polarity and voltage is as specified by the products.

 

[Neil H]

Thanks for the help guys. I can never get photos onto these forums for some reason, here's the pictures on flicker.

Board with connector..

Marshall board full e - https://www.flickr.com/photos/72122298@N04/34757455966/in/dateposted-public/

Close up of chip with residue, do you think this chip would get hot?

Marshall board chip 2 e - https://www.flickr.com/photos/72122298@N04/34664933551/in/dateposted-public/

 

[Neil H]

 

[Neil H]

I've tried posting the images a few times but with no luck, I've 2 posts with links to the images on Flicker but they are pending moderator approval.

 

[Pete999]

So I have been renovating some old Steadicams. These run off V mount batteries on the bottom brackets which feeds power to the camera and accessories on the top stage and the monitor on the bottom bracket.

Electrics is not something I know too much about but I’ve tried to do some research and taught myself to solder. I installed all the wiring and sockets and made up all the cables for the power and the video feed from the camera to the monitor and everything worked fine but my monitors SDI video input is broken. It’s a good monitor that would cost a lot of money to replace and the HDMI input works fine so I found a little SDI to HDMI converter. The converter though needs power too, 5V DC, and came with it’s own power cable that plugs into the wall. I plugged it in, fed the SDI video signal into the converter and then the HDMI out of the converter into the monitor. Plugged the monitor into the battery on the Steadicam and tested the signal. The converter worked great, no lag, good signal.


But obviously it’ll need to run off the steadicam battery too so I split the power cable coming from the battery to the monitor and put two DC plugs on it, one for the monitor and one for the SDI-HDMI converter and plugged them both in. I put the camera on the steadicam and plugged the video SDI into the converter and the HDMI from the converter into the monitor and before I could check for a signal smoke came out of the top of the monitor. I quickly unplugged everything.

I checked my monitor and it still works fine with the HDMI feed in but obviously I don’t want to plug everything back in as it was. What I was thinking was that there must be power coming down the HDMI and causing a short in the monitor. I checked all the cables again and they are all fine so I checked what was coming down the HDMI and it’s about 5V. I plugged the converter into the battery and the wall and checked both, they both have about 5V coming down the HDMI.

Do you think I’m right or have I missed something? I do need to put a boost buck on the power supply and I’m wondering if this would isolate the monitor/converter? Or will this set up never work without a separate battery for the converter. Or just biting the bullet for a new monitor. Any advice appreciated.

It's on fire

 

[Wilko]

You probably already know, but that's the HDMI processor - sure it's not been powered by 12v when it should be 5v or some such?

 

[Neil H]

No I did't know but I just had a look and found the chip that has the residue on it. It’s made by a company called Analog Devices and it’s a .. “The ADV7612 is a high quality, 2:1 multiplexed high-definition multimedia interface (HDMI®) receiver.” So the burnt plastic connector was probably just wishful thinking, it would be too much of a coincidence that the chip that receives the HDMI signal would be damaged.

As for what voltage the chip receives, it's part of one of the boards inside the monitor. The monitor takes 12V as do most field monitor and it's marked clearly on the power socket, what the actual voltage is the chip receives would be down to the board design.

I opened it back up, carefully removed the residue from the top of the chip with the tip of a pin and a soft makeup brush then took this macro photo of the damage...

chip 7 e - https://www.flickr.com/photos/72122298@N04/33958235854/in/dateposted-public/

Not pretty, the juice must of oozed out of here as it was going up in flames. I'm amazed the thing still works.

 

[Specialist]

Hmm, you made a mess of that. Only way to get that replaced is to take it to some with an SMD Re-work facility.

 

[Neil H]

I still don't understand. If the converter wasn't being use then the signal would be coming from the camera via HDMI and the monitor would still be both powered from and getting the HDMI signal from the same power supply, but this is the normal configuration it works fine in.

The only thing I could think of was that 5v should not be coming down the HDMI feed, So I found another camera and measure the voltage coming down the HDMI and it's the same, 5V. So 5V is perfectly normal for a HDMI video feed.

So if it's always 5V coming down the HDMI, why if the camera and monitor are plugged into the same battery it works fine, or if the HDMI converter and the monitor are plugged into separate batteries it works fine but if the HDMI converter and the monitor are plugged into the same power supply it fries the chip?

 

[Neil H]

I'm not off line, I don't know why it says I am.