06-23-2015, 04:26 PM
The resistors are marked as being 270 ohm. The last digit is number of zeroes . The black boxes with grey band are most likely diodes. To test that use diode measurement with the black lead on the band. Zener diode will measure as an ordinary diode the other way around so check that too. Diodes commonly have voltage drop of 0.2-.7V.