How to Adjust the Laser in Your DVD Player

By Techwalla Electronics Editor

If your DVD player is giving you a lot of noisy playback or poor tracking, your laser could be losing strength and need adjustment. If you've tried other alternatives and believe you have nothing to lose in adjusting your laser, follow the steps below.

Things You'll Need

  • Oscilloscope
  • DVD player

Step 1

Make sure your lens is completely clean. Sometimes the problem lies in a dirty lens and not in the strength of the laser. You need to eliminate simple possibilities first.

Step 2

Check your owner's manual to see if it has instructions for adjusting the laser in your DVD player. Follow your manufacturer's specific instructions.

Step 3

Borrow or purchase an oscilloscope. Though having one is not necessary, if you are not able to track the visual output, there is the chance of turning it up too high without realizing it and destroying your laser.

Step 4

Put the probe on the RF test point. With the disc playing, notice the eye pattern. Mark the exact amplitude of the peaks. Be sure to notice the playback quality, so you have something to compare it to.

Step 5

Turn off the power to the DVD player. Make sure you've noted the exact position of the laser power adjustment so you can refer back to it.

Step 6

Turn the control a tiny bit clockwise. This control is very sensitive and you can easily over adjust and destroy the laser.

Step 7

Turn the power to the DVD player back on. Note the eye pattern after the change. You should see the amplitude change. If it changed in the wrong direction, then you need to adjust the control in the opposite direction.

Step 8

Notice if there has been a change to the playback quality. If not, then your laser is probably not the piece at fault. If the eye pattern has not changed either, this could signal that it is at its limit and at the end of its life.

Tips & Warnings

  • Typical values for the eye pattern should be in the 1 to 2 V range. If there are a few hundred mV or less, then there is a larger problem.
  • Do not attempt to adjust the laser unless you feel comfortable doing so.
  • If your DVD player is still covered under warranty, take it to in for repair and do not attempt this on your own.
  • Do not continue to raise the control higher unless you have exhausted all other alternatives. The higher the amplitude the more risk you impose on the laser.