is this a diode? what is the value or replacement I can use.
- Thread starter luchura
- Start date
The type component that most commonly shows a number+A would be a fuse. I do agree that the 3 lines are confusing for a fuse. If it were removed from the board, an ohmmeter could easily confirm either a direct short or an open, with no sensitivity to polarity.
On the board there is a D##### next to it. I removed from the board, there is no other code. Tested for continuity and both ways current flows. Must be a bad diode. I looked other parts of the board for similar component and there was a similar with a 33 A on it. It was a diode because only one way current flows with the multimeter. on the board there is a D#### next to it.
Here is a picture of the other diode.
Here is a picture of the other diode.
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MisterBill2
- Joined Jan 23, 2018
- 18,475
It does look like a diode, and a good guess is that it is a 6 volt zener diode. But to verify that you should trace out a bit of the circuit to see how it fits in. Guesses, even good guesses, are a poor substitute for knowing.
35 years inspecting PCB's with components, I've watched them get smaller and smaller. So small that they can not put the full identification number on them. 33A and 6.0A are proprietary markings by the component manufacturer. It's been a while and I think I have a listing on my other computer, but you're going to need to know the manufacturer in order to decypher the number code.
Yes, it's a diode. The three striations on one end indicate the cathode end. As for size, type or purpose, you'll need to know the manufacturers code. Since you can't tell the manufacturer - at least not that I'd know - it's not possible to know what type of component it is. Other than a diode that is. Zener, Schottky, or regular diode - can't be discerned from the markings.
If you can get a parts list - the D### only references the component to the bill of materials (BOM). I just grabbed a board with some diodes (and other stuff) on it. One such diode is marked D701. All that means is that on that particular board is that D701 is the BOM item number. R701 would be just one of the resistors on it. Could be a bunch of resistors are the same - such as a 4.7KΩ resistor. Could be R701, R702, R708, R711 and so on. While R703 - R707 are 22KΩ. Or whatever the manufacturer said it was when they built the BOM. Same is true with diodes, capacitors (C780), transistors (typically but not always) Q701, coils L701 and microchips U701. All the number on the board means is what part the BOM wants put in at that location.
If your diode is conducting in both directions - it doesn't mean it's shorted. Very likely it is - but I've seen diodes that conduct in both directions. Designed that way. Sorry, I can't give you an example of such. What would be the purpose? Couldn't answer that either. But I swear I've seen them. Though I can think of one example - a bi-colored LED. Conduct in one direction you get red. The other - blue. There are some strange beasts out there for sure.
Your best hope is to decipher the circuitry if you can. Single and double layer boards can be drawn out, although somewhat painstakingly. Multi-layer boards (inner layers that can't be easily seen) are impossible to decipher. But if you can, once a circuit becomes obvious you can then convert that drawing into a schematic. Then, with components identified, we can begin to suggest what that part might be. But for now - it's a diode. That's all any of us will be able to tell you.
Yes, it's a diode. The three striations on one end indicate the cathode end. As for size, type or purpose, you'll need to know the manufacturers code. Since you can't tell the manufacturer - at least not that I'd know - it's not possible to know what type of component it is. Other than a diode that is. Zener, Schottky, or regular diode - can't be discerned from the markings.
If you can get a parts list - the D### only references the component to the bill of materials (BOM). I just grabbed a board with some diodes (and other stuff) on it. One such diode is marked D701. All that means is that on that particular board is that D701 is the BOM item number. R701 would be just one of the resistors on it. Could be a bunch of resistors are the same - such as a 4.7KΩ resistor. Could be R701, R702, R708, R711 and so on. While R703 - R707 are 22KΩ. Or whatever the manufacturer said it was when they built the BOM. Same is true with diodes, capacitors (C780), transistors (typically but not always) Q701, coils L701 and microchips U701. All the number on the board means is what part the BOM wants put in at that location.
If your diode is conducting in both directions - it doesn't mean it's shorted. Very likely it is - but I've seen diodes that conduct in both directions. Designed that way. Sorry, I can't give you an example of such. What would be the purpose? Couldn't answer that either. But I swear I've seen them. Though I can think of one example - a bi-colored LED. Conduct in one direction you get red. The other - blue. There are some strange beasts out there for sure.
Your best hope is to decipher the circuitry if you can. Single and double layer boards can be drawn out, although somewhat painstakingly. Multi-layer boards (inner layers that can't be easily seen) are impossible to decipher. But if you can, once a circuit becomes obvious you can then convert that drawing into a schematic. Then, with components identified, we can begin to suggest what that part might be. But for now - it's a diode. That's all any of us will be able to tell you.
Here is a webpage that MIGHT help you get an idea what your component is. Look carefully. There are a number of possibilities. I'm just hoping someone has decided to make markings according to a universal standardized code. From what I'm reading - it might be a transient voltage suppressor.
