Confused when it comes to "I" and "1" when it comes to SMD marking codes

[mitsu2k]

Hello folks, I seem to have a lot of trouble when it comes to distinguishing markings on SMD components especially when it comes to the question of whether it is a 1 or an I. for example, I see components marked NI. It looks just like that. However, I cannot tell if that "I" might be a number one instead. Is there a rule of thumb that manufacturers use when using these characters? Attached is an example. This is just one example out of many I come across but it's a good illustration of my point. I appreciate any input.

[truclacicr]

I'm confused also. Another common example is "oh" and "zero".

[mitsu2k]

I'm confused also. Another common example is "oh" and "zero".

Yes that is another good example. There are a lot of smart folks on these forums. I hope someone here can shed some light on this.

What I normally try and do is go through the SMD database and do a process of elimination using the package type of the devices and rule things either in or out. That doesn’t always work though as there can be multiple that fit the criteria.

[harp]

It is diode with marking WI, so google it and you will see a similar one described like zener diode 13V - BZT52C13. Then check this label to confirm in datasheet.

Is there a rule of thumb that manufacturers use when using these characters?

Yes, they do mess whenever it can

[mitsu2k]

It is diode with marking WI, so google it and you will see a similar one described like zener diode 13V - BZT52C13. Then check this label to confirm in datasheet.



Yes, they do mess whenever it can

Ok in the example of “WI”, you are correct it is a zener but it is not 13v. I know that is what all the SMD databases say but in this case it is a 3.6v zener. I know this because I removed a few other good ones from the board and tested them.

[sam_sam_sam]

Ok in the example of “WI”, you are correct it is a zener but it is not 13v. I know that is what all the SMD databases say but in this case it is a 3.6v zener. I know this because I removed a few other good ones from the board and tested them.

mitsu2k

So here is a question if you do not have another complete working device that has a good part device that you are trying to figure out what it is how do you know that you have picked the right one so that the complete non device is working correctly with device part that you used especially when you do not know exactly what the device is in the first place yes I know that you can assume something but that is like a crapshoot at best

[mitsu2k]

mitsu2k

So here is a question if you do not have another complete working device that has a good part device that you are trying to figure out what it is how do you know that you have picked the right one so that the complete non device is working correctly with device part that you used especially when you do not know exactly what the device is in the first place yes I know that you can assume something but that is like a crapshoot at best

Yes you are correct. It is a crapshoot. Best way is to have a working device that you can compare. Markings are often times duplicated by different manufacturers for different parts