LG nb3530a Zener Diode Identification

[mikay786]

Ive got a shorted zener diode on a power board for a sub but struggling to make sense of the markings to identify a replacement.

From what i can make out says 33B5T

This is what a google brings up

https://datasheetspdf.com/pdf/102878...ents/MZC33B5/1

Was looking at this as a replacement 3.3v Is this suitable?

https://www.ebay.co.uk/itm/161636082...Cclp%3A2334524

[R_J]

Re: Zener Diode Identification

What Make & Model sub? it could be a 33v zener (33BST)

[mikay786]

Re: Zener Diode Identification

What Make & Model sub? it could be a 33v zener (33BST)

It’s just a wireless sub part of a LG sound bar setup


LG nb3530a

Actually found another shorted zener directly after a octocupler from the primary to secondary side.

I’ll get some board pics up shortly

And yes the 5 could be a S, so 33BST

I’ve just bought a kit of Amazon which includes loads of values

[CrimsonKyber96]

Re: Zener Diode Identification

I have the same problem and I stumbled upon this thread.

Did you manage to solve your problem? If so what value zener diodes did you use as replacements?

I have two shorted zeners on the output of the optocoupler. One zener diode on the feedback pin and one on VCC. The feedback pin has a max rating of 5V and VCC has a max rating of 25V. Wouldn't this mean 33V zeners are unsuitable?

[stj]

Re: Zener Diode Identification

I've just bought a kit of Amazon which includes loads of values

like mine?
https://www.aliexpress.com/item/1005001780550855.html

[stj]

Re: Zener Diode Identification

I have the same problem and I stumbled upon this thread.

Did you manage to solve your problem? If so what value zener diodes did you use as replacements?

I have two shorted zeners on the output of the optocoupler. One zener diode on the feedback pin and one on VCC. The feedback pin has a max rating of 5V and VCC has a max rating of 25V. Wouldn't this mean 33V zeners are unsuitable?

why not read the print on the shorted ones?

[CrimsonKyber96]

Re: Zener Diode Identification

why not read the print on the shorted ones?

The print reads 33B5T and I can't find any information regarding the values online. I've been searching for the past few hours for a data sheet that looks something like but I've had no luck.

[lotas]

Re: Zener Diode Identification

Rather, a regular 33v zener diode (stands in the role of power protection).

[lotas]

Re: LG nb3530a Zener Diode Identification

found a circuit for the power supply:
ZD901 - 33V
ZD902 - 22V
ZD906 - 10V
ZD908 - 5.1V

[radio-ged]

Re: LG nb3530a Zener Diode Identification

Very helpful info - thank you.

[dkneyle]

Re: LG nb3530a Zener Diode Identification

yep, standard design appears to be to use a 33v zener in that position