Hello all. I am trying to repair a power supply board that was damaged when my house was struck by lightning. The extent of the damage (that I can see) is a blown fuse and a completely annihilated other component that I am unfamiliar with. I was able to find a photo of the board and blow up the piece in question, could anybody here shed some light onto what it might be? In this pic it is labeled GA7001, but that seems to be a location number (the 7001 part anyway) as I have not been able to find any information about it. I did find a schematic for the TV but this board was only references as a whole unit so no help there.

Here is the picture:

Thanks in advance for any assistance!

Justin

 

In this pic it is labeled GA7001,

It looks like a Diode. Switching Diodes like the 1N914 are usually glass encapsulated like that. Should be easy enough to check with an Ohmmeter.

 

I cannot check mine with a meter because it is completely blown out. The only thing I have is 2 wires sticking up from the board with pink glass on each.....

 

it could be diode, zener diode, suppressor...

 

Since the nearby devices are a fuse and what appear to be varistors, I would hazard a guess that it was a surge suppresion device such as gas filled spark gap. If it is BLOWN that tells me it performed its function and took the death dealing surge to ground(lightning strike perhaps)

 

Since the nearby devices are a fuse and what appear to be varistors, I would hazard a guess that it was a surge suppresion device such as gas filled spark gap. If it is BLOWN that tells me it performed its function and took the death dealing surge to ground(lightning strike perhaps)

... and if it is indeed a spark gap it should work without it although you may not get off has lightly next time!

 

Call the company and talk to tech support, tell them you are in electronics repair and ask them if they can provide information on that part to repair a customers TV that was brought in to you.

 

Since the nearby devices are a fuse and what appear to be varistors, I would hazard a guess that it was a surge suppresion device such as gas filled spark gap. <snip>

Yo, Mr. Monk! I like that call. Sooo, "this is what happened" and lightning... "He's the guy"?

 

Since the nearby devices are a fuse and what appear to be varistors, I would hazard a guess that it was a surge suppresion device such as gas filled spark gap. If it is BLOWN that tells me it performed its function and took the death dealing surge to ground(lightning strike perhaps)

+1, because it is near two blue devices which I am quite sure are Varistors. This all looks like circuitry designed to blow under an input voltage surge.

 

I think it's a gas discharge tube for transient protection. The "GA" probably is short for GAs or Gas Arrestor.

 

I suspect the GA stands for Gallium Arsenide. This would suggest is a type of diode.

 

It could be an ordinary 1A 600V rectifier diode. It's reverse biased as a protection diode would be. If the color code is reliable, it could be a 1N3613. Other code variants such as 1N361C and 1N61C don't generate valid results.

http://www.microsemi.com/en/products/product-directory/2152

I've never seen a GDT in that form factor.

 

I've never seen a GDT in that form factor.

Neither have I, but it is in the power supply section, adjacent to the varistors, and it looks like it's attached to ground through a fuse, which would be typical of a GDT/GPA.

 

I actually posted a suggestion to the OP's duplicate thread on another forum site that the device is an avalanche diode. They are often used as a substitute for a GDT and would compliment the MOVs with faster speed. I think we can safely assume that it's some form of circuit protection device designed to short a high voltage transient to ground and simply choose a device based on the voltage present at that point in the circuit. The OP can put in an avalanche diode, GDT or TVS that's faster and can handle more voltage and current than the original would have since he's not concerned with value engineering the unit cost down; he just wants to fix his TV without buying the whole board ($75 online).