Identify this part?

[CXTURBO]

Edited to place the image in the post - for easier viewing.

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Hello,
This is my first time posting.
I am trying to find the P/N from the part's marking.
If you know it, please let me know.

Engraving: GP229

Guess: Schottky barrier diode STPS2L60 - 2A, 60V. Is that correct...?

If you have any information, please let me know. Thank you.

[AScha.3]

Hi,

marking could be ... GU

Look, what it should do probably in the board : diode or ESD protection ?

[Peter BENSCH]

Welcome @CXTURBO , to the community!

You'll find the marking in the 2nd line, i.e. U12.

Unfortunately, the marking is ambiguous and could refer to either STTH102 (Utrafast 200V) or STTH112 (Utrafast 1.2kV) , which differ significantly from the blocking voltage and the forward voltage. For a successful replacement, you should therefore try to find out what the maximum voltage can be.

Regards
/Peter

[CXTURBO]

Thank you for getting in touch.
I repair faulty power supplies, circuit boards, etc. that are entrusted to me by customers.
In this case, I needed this diode to repair an AC servo driver.
As I don't have a circuit diagram, I don't know its purpose (protection, ESD, etc.).
I plan to create a circuit diagram depending on the situation, but I was in a difficult situation as I couldn't install an uncertain part.
Is it likely that the SM6T200A mentioned in your comments is the P/N?
Also, is there a way to identify the P/N from the engraving?
Thank you in advance.

Please excuse any strange notation as I am using Japanese translation software.

[CXTURBO]

I'm sorry I don't really understand how to use it.
Regarding the STTH102/112, as advised by Peter, I'd like to remove the parts and measure them.
I'll comment once I've finished checking.
Thank you in advance.

[CXTURBO]

For your reference, I have included a photo of the defective parts.

[CXTURBO]

Hello

I tested the part by applying a voltage.
The results showed that no current flowed even when a reverse voltage of up to 1 kV was applied.
Since the voltage cannot be increased any further, it is unclear at what voltage current will flow.
Can we confirm that it is the STTH112?

[Peter BENSCH]

If no forward voltage can be measured at the diodes in the forward direction, there is no point in testing them in reverse – dead is dead. It is more a question of the voltage that can occur in the circuit.

If you do not know the reverse voltage, for example because you do not have any documentation, you can start by using the STTH112. This should make it work again and you can observe the voltage curves, preferably with an oscilloscope. If you see voltage peaks significantly lower than 200V, you can install the STTH102, which also produces significantly less power loss due to the lower forward voltage.

Good luck!
/Peter

[CXTURBO]

Hello
Thank you for contacting me.
I checked the datasheet again based on your advice.
I mistakenly thought it was a Zener diode.
The correct answer is a fast recovery diode.
So, my checking method yesterday was incorrect.
I will check the characteristics on the datasheet again and think about it.

[CXTURBO · Accepted solution]

Sorry for the late reply.
I obtained two candidate types and made a decision.
In the end, it appears that STTH112 was the correct answer.
STTH112 does not conduct current even at 1KV or reverse voltage, but STTH102 did.
Now I can install it with confidence.
Thank you for your advice.