I know many folks on this forum warn against conductive glue and suggest removing it immediately upon site. I'm here to vouch and say these people know what they are talking about. To be more accurate, the glue isn't intended to be and doesn't actually start out conductive. It gets conductive as it is heated by components that get hot. The glue starts out to be a light tan color but as it is exposed to heat, it gets darker and darker until it is a dark brown. I have found that it becomes conductive at the point that it reaches a light brown color on darker.
Here is an experience I had yesterday. I purchased a Monster surge protector as a parts donor for another repair. I decided to plug it in just for the hell of it so I can get an idea if it even powers on. The instant I plugged it in, I heard a loud sound that almost sounded like a blow torch. Of course I recognized the sound and immediately pulled the plug within a fraction of a second. Upon opening it up? I saw and smelled the smoke and soot that I expected to see. Attached are some photos of the damage. On the first photo I have placed a yellow rectangle. There was a jumper there but now completely burned away . Also on that photo you will see a diode with the Anode leg completely burned off. If you look at where the Anode side of the diode is, there is a hole burned all the way through the board. That leg acted as if a torch and burned through the board. Believe it or not but I tested that diode since there was barely a stub coming out of the body and the diode is still good. The transformer is also good. After replacing the jumper, the diode, the burnt PCB traces and the capacitor (just for good measure) you see in the picture, the unit now works perfectly.
What is the significance of all this? Well, there were no components that were faulty to cause this short. This was caused by the glue that was bridging the jumper with the Anode side of the diode which when the glue got conductive enough, POOF!! Luckily I had the power cord in my hand at the moment this happened and was able to pull the plug really quick. But this can happen at any time and has the potential to cause a fire especially if the housing of the device is made of wood (such as a subwoofer) or plastic.
Here is an experience I had yesterday. I purchased a Monster surge protector as a parts donor for another repair. I decided to plug it in just for the hell of it so I can get an idea if it even powers on. The instant I plugged it in, I heard a loud sound that almost sounded like a blow torch. Of course I recognized the sound and immediately pulled the plug within a fraction of a second. Upon opening it up? I saw and smelled the smoke and soot that I expected to see. Attached are some photos of the damage. On the first photo I have placed a yellow rectangle. There was a jumper there but now completely burned away . Also on that photo you will see a diode with the Anode leg completely burned off. If you look at where the Anode side of the diode is, there is a hole burned all the way through the board. That leg acted as if a torch and burned through the board. Believe it or not but I tested that diode since there was barely a stub coming out of the body and the diode is still good. The transformer is also good. After replacing the jumper, the diode, the burnt PCB traces and the capacitor (just for good measure) you see in the picture, the unit now works perfectly.
What is the significance of all this? Well, there were no components that were faulty to cause this short. This was caused by the glue that was bridging the jumper with the Anode side of the diode which when the glue got conductive enough, POOF!! Luckily I had the power cord in my hand at the moment this happened and was able to pull the plug really quick. But this can happen at any time and has the potential to cause a fire especially if the housing of the device is made of wood (such as a subwoofer) or plastic.
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