顾老师，向你求教D50mkII

manjiang2024

   前辈你好：
   我是顺着家电论坛找过来的，学习了你的帖子，学到了不少。
   现在我遇到一个D50MKII，修理完主板测试，一切正常。按手册测量，推算出光头功率被上家调超过了15%，目测光头电位器也超过了正常范围。
   测试完后放了两天，莫名的不读碟，我怀疑光头刚好被我遇到洗白白的时候，不知道我的猜测是否合理，还请前辈指导，若是换激光管，在没有专业设备的情况下，显微镜能否做到您说的对靶？另外询问了一些同行，说是：主要问题是光路污染和光路偏移，如果是，如何调整呢？
  给你添麻烦了

  再次感谢

kaosun

The original position of the laser power potentiometer on the laser optical head is almost at the max position.  Further, a potentiometer at its max position has weak resolution and bad contact. Usually I replace it be 1K OHM  and adjust it to be like 650OHM. You can measure the resistance of the pot like you get 600OHM, then replace the pot to be 1K OHM, adjust the new pot to be 600OHM, then check the laser power/RF eye pattern. I guess your issue of not reading is laser power related. Do not replace laser diode now if you have no microscope and qualified laser diode, it's not a easy job for you.