Audioreview.com NAD 522
It is the same fault that I fixed in my Kenwood DP-4030 about 20 years ago, which incidentally is still going strong. There is a potentiometer on the laser pickup board that adjusts the laser voltage.
If you are lucky enough to possess an oscilloscope it is easy to adjust the peak to peak value to 2.4V & ensure the waveform is focused. If not & you are like me, you just have to use your ears, though a voltmeter is helpful to record the resistance across the potentiometer. This helps not to lose your place as you adjust it. Too little voltage and your home recorded cds won't read & too much will saturate the signal resulting in distortion & a burnt out laser. It is a case of measuring the upper & lower limits of resistance & tuning the pot to the middle of the range.
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