Read value of SMD diode (mini-melf)

Hi,
I've a problem with a switching power supply and I've found a diode in short circuit. It's a SMD component, minimelf with only one blue band... I've found that it's a zener diode, but nothing other info on it's body as you can see from the photo (ZD1).
How do I know its value to replace it?

Thanks,
Sebastian

If it's a zener, read the voltage across the good one.
Zeners act like a simple voltage regulator in their effect.

Hi,
I know as a zener diode works, but the problem is that they are not the same (you need to enlarge the photo to view differences).

Thanks,
Sebastian

cant see any difference

care to tell us why you think they are different ?

Dave

One of the two blue bands is smaller, the body inside the glass have different orange color (one more dark) and size (the interruption between the two bodies seems shifted)...

Remove the defective zener first then read hidden label around the zener using magnifying glass.

Hi,
I've already desoldered the SMD diode, only the photo was done with component mounted, but there is no written on the body (I use a 10x magnifier) so I've decided to do a post here if someone can help me.

The only way we can assume the zener voltage value was you have to trace the portion of circuit.. Much better if you include voltage value of capacitors, name of ic, optocuplers etch connected to defective of the zener diode.. Post that portion of schematic.

Then, we can help you.

could easily fall within manufacturing variations

Dave

Hi,
the object is a switching power supply, output 9V 1,3A.
The mosfet is a STK0460F (removed because I must replace it), no optoisolator on circuit, precision shunt regulator TL431.
The SMD diode removed is connected to the single pin of SMD transistor.
If you need other info ask to me.

Thanks,
Sebastian