Not sure about testing diode in circuit

[taste_tester]

I was trying to find a fault in this schematic to find my faulty component.
I tested all the values shown and everything was correct and in spec 

I did diode test on CR13, CR14.
Vdrop with the leads facing the normal direction, 0.64v.
Vdrop with the leads facing the wrong direction, 1.715v.

I thought there should be nothing in the wrong direction, but i'm not sure because I'm testing in circuit.
Both diodes show the same measurement, within 0.02v +/-.

Should I replace the diodes? Or are they not the problem?

[wn1fju]

Those diodes are use to clamp the voltage.  They are most likely OK and the reverse reading you are getting is the result of looking back through the power supply and other circuitry.  If you want a definitive test, simply de-solder one of the leads of each diode and test them that way.

I would also suggest you look at the op-amp.  A very simple check is to measure the voltages at the inputs - they should be the same when the unit is operating.  Pins 5 and 6, and pins 9 and 10 should all be at zero volts.