I am attempting to repair a circuit board where this particular Zener Diode is fried. I have attempted to search for any references to Zener diodes that are marked 8•9 (and 6•8) without success.

How can I identify a suitable replacement?

SMD zener diode with 8•9 marking

The approximate dimensions are 0.8mm x 1mm x 2mm.

  • 2
    \$\begingroup\$ Is there another one on the board? What is the zener for (what is it's function in the circuit)? How do you know it's dead? \$\endgroup\$ – Voltage Spike Jul 29 at 0:16
  • \$\begingroup\$ I am sure that it's dead because it has the appearance of being scorched and burned, after emitting a small whiff of smoke. I believe its purpose is protection for a panel indicator LED which I wanted to bench test by applying power directly to the LED. But I applied power (2.4v) with reversed polarity which fried this diode. \$\endgroup\$ – ddoxey Jul 29 at 1:19

Maybe it is a HZU6.8B2JTRF, a Zener with 6.8V Zener voltage.

  • 1
    \$\begingroup\$ COrrect. THe bar is read from the left side and 6.8V Zeners are standard while 8.6 are not yet 8.5 and 8.7 are std. Probably the 1W package \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 Jul 29 at 1:00

To go about identifying a replacement, read the marking with the polarity bar to the left, which indicates 6•8.

A close replacement could be:

  • Package: SOD-123-2
  • Power: 1W
  • Zener Voltage: 6.8V

I'm going with the MCC part number DFLZ6V8-TP.

I found the image view on mouser.com to be helpful in choosing an approximate package type: https://www.mouser.com/Semiconductors/Discrete-Semiconductors/Diodes-Rectifiers/Zener-Diodes/Images/_/N-ax1mh?P=1z0z7pt

Knowing the zV and package type narrowed the options down to 1W.


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