zener diode value

[pan2]

I've found a dead zener diode in an outside unit pcb of my split system (shorted out). Trouble is, it's so small any attempt at reading it's value, well :( It appears to be the only zener on the board and part of a voltage regulator. It is a RXE35B external unit.Ive attached a close up if that helps. Any guesses at it's value would be most appreciated

[Jim_H_WY]

Is the diode visible in that photo, or just a place on the board where it belonged? I see a location marked "ZD1" which looks to be where a zener used to be located. There's no way to know its value just by viewing the place where it used to go on the board.

We'd need a schematic if we were going to try to infer its value from the surrounding circuitry.

Or we'd need a non-damaged circuit board to compare or test.

If the diode burned up, it will likely be impossible to read the part number. But if the diode is physically intact, there should be a part number on it even if it is very small.

You will almost certainly need to remove the diode from the board to read it's part number because you never get lucky enough to have the number entirely visible. But it looks like you already removed the diode.

You may need magnification and a good light to read the part number.

If you're really unlucky, then the zener will have burned up such that the part number is unreadable OR the part may be "house numbered" with a useless assembly number instead of a "good" number that can be cross-referenced.

Do you still have the diode? Is it burned up?

If you've got it, and it's not burned up, then the part number should be readable.

[pan2]

Thanks Jim but even under strong magnification it was difficult to tell if it was a 5, so I took a guess at 5.6V :) replaced for 55c (AUS) and everything worked :) so much for replacing the pcb :)