It was a quick example, you can encounter these on hardware or electricity stores everywhere.kamiboy wrote: Yes, well, eBay is alway an option, if you don't mind waiting two weeks for your item to arrive, because that is how long it takes me to get anything I buy from there. But before we go that far let me try and understand the scenarios a little better, then at least I can diagnose similar problems better in the future.
Voltages are always measured between two points. Grounds represent the 0V reference of a signal. They also can close electric circuits so that charges can circulate indefinitely.kamiboy wrote: Then there is disconnected grounds. Now, this one I cannot figure out, I don't know much about electronics, I don't even know what the use of grounds are. Perhaps you could walk me through what the purpose of these grounds are in the scart and how they can cause buzzing, and if they indeed are to blame, how I would go about fixing them.
The chassis ground is a safety ground, and it is not always connected. If you have a conductor connected to earth around the cable it would discharge any high voltage to ground and trip the electric breakers.kamiboy wrote: Looking at SCART digagrams I seem to see a supposed line going from the metal socket head connecting together several of the pins. I figure this is what is meant by ground connections to the chassis. I doubt all these connections are supposed to be made manually, as in via a wire, because I have never seen such a thing inside any SCART head, so I assume there is some sort of internal connection between these.
Is preapplied solder in the connector and if there is no cable soldered it has no effect.kamiboy wrote: I've notticed that the ends of some unused pins are filled with some sort of solder like filling, where as some are left hollow. Are these fillings what causes the ground connection to happen?
As I said before, to measure a voltage you need two points, and if you don't connect the ground the readings are incorrect (they usually depend on the measuring circuit). In the case of audio they manifest as buzzing and in video it can invert the video.kamiboy wrote: But for starters talk me through a scenario where grounds are at fault. Let us pretend I bought a multimeter and two weeks have passed and I have it. What would I do to measure if anything is wrong? The connection between two pins in the had? Perhaps, say, pin 4 (Audio GND) and pin 1 (Audio R)?
If two electronic devices don't agree in the ground (roughly, their grounds are not connected) you have a problem. This is very simplified, there are different types of ground to consider (for example, there is a ground pin in your wall socket.
To detect unconnected grounds you can test with the ohmnimeter between corresponding ground leads in the cable ends. If the resistance is not 0, you hace a unconnected ground or a broken cable. The solution would be to solder a cable connecting both.kamiboy wrote: Or would it be between a pin in the din connector and one in the head? Say I do the measurement and something is off, what would I then have to do to fix it? I would appreciate any one walking me through this.
In the case of SCART cables, you can usually connect all the different grounds togheter, but it is better if each has a cable.
I did cut open the SCART case on the back because the 3 220uF Caps were too big to fit in the casing. 
