Information about zener

[rmoyao]

Hi everybody.

Does anyone knows the component in the attached photo. I believe is a zener diode. It comes from a ECU from a car but I haven't been able to find any specifications so I can't find a replacement or a equivalent part.

Any help will be greatly appreciated

[watchmaker]

Hi everybody.

Does anyone knows the component in the attached photo. I believe is a zener diode. It comes from a ECU from a car but I haven't been able to find any specifications so I can't find a replacement or a equivalent part.

Any help will be greatly appreciated

Scroll down to post 22 on this link:  https://subaru-svx.net/forum/showthread.php?t=59362&page=2

Did not read the whole thread but it looks like he got help.

[rmoyao]

Thanks for your answer.

I red that thread before but unfortunately  the specification of 7.2V 10W does not seems to be correct in my case. The thread is about what it seems to be a light control in my case the zenner is used on an ECU so I need to know the exact voltage and power for the part.

The two components that they recommend have different voltages so it is not clear.

I was hoping someone in the forum would know this specific part as it seems that it has been discontinued long time ago.

Thanks

 

[floobydust]

From the Subaru board pics, this is a standard automotive TVS diode Nippon Denso used, in a 1980's button package which is obsolete.
It is protecting the dimmer board and everything downstream from overvoltage transients and load-dump. Very hard to blow one of these diodes. As you can see, the PCB trace fuses first. What happened to it? I think this board protects power for a bunch of other stuff.
It's a Japanese semi, the "T" might be Toshiba, but yellow lettering was Hitachi as I recall. It could be Sanken as well. I could not find the part number "S 5225" anywhere.

Modern parts are plastic, the standard is "27V" yet popular parts available are either 26V or 28V. The exact voltage value is not critical. I would use a 5KP26A (surge rating 5,000W) and make sure it can fit as it's 2mm longer body. Smaller (surge rating 1,500W) part would be 1.5KE27A OK if you don't drive around with a bad battery connection or have a crap electrical system.
Original part could be 3,000W like (plastic) ZSA5A27.
The damage to the board (melted traces) is due to pulling way too much current through it from a wiring mistake somewhere else.
The other parts are vanilla on the board if you need help fixing it.

[Andreas]

Hello,

I would use a LDP24A as replacement. (check for correct polarity)
https://www.digikey.de/de/products/detail/stmicroelectronics/LDP24A/1038441

Why do you suspect that your diode is defective?
Usually they make a "short" in both directions on over load.

With best regards

Andreas