Hi Sir. Jestine,

Is it okay I got 2 readings in diode SR204? Noted to the pictures that I have sent to you. Please help me and thank you in advance.




A.P

test diode

Reply:

Hi A.P

When test a diode you should remove one pin from the board and test it with an analogue meter using x10 K ohm range. If you test on-board this means you are checking on the parallel circuit as well which eventually will give a wrong reading. You need to take out at least one pin (leg) from the circuit board in order to perform the accurate testing on diode. For a normal diode it should have only one reading. For a schottky diode some will have one reading and some will have two readings but not shorted reading. Example, if you check on a 1N5817 schottky diode you will get two readings but not shorted reading. If you check on SB5100 Schottky diode you will only get one reading when test it both ways. If you get two similar readings means it is shorted.

Jestine

About

Jestine Yong works as an Electronics Repair Lecturer in Kuala Lumpur Malaysia and his training website is http://www.NoahtechElectronicsTraining.com. You can check out his repair blog at http://www.JestineYong.com