Strange diode voltage drop?

Question

Do it yourself

Good day to all.
Actually the situation is as follows: we have a board, there is a diode on the board. We take a multimeter, put it in the diode test mode and check it. In one direction, the multimeter shows 156 , in the other 484 .
As far as I remember (about my 2nd course), diodes should only conduct current in one direction, but there is a very big difference here. In this regard, the question is: is the diode serviceable or does it need to be replaced?
UPD
I checked it on the board, I did not solder it. The board itself is disconnected from the voltage and has not been connected to the power supply for 3-4 days.

Answer 1

Regardless of whether there is voltage on the board, the diode still needs to be unsoldered for testing - otherwise the current may find its way "around" the diode, thereby creating a voltage drop, which you measure with a multimeter. If you show the diagram, I'll even find you the conductivity of what exactly you actually measured :)