Not because you read the CDs you necessarily have to read the DVDs. Keep in mind that on the one hand the DVD has to reach many more revolutions than a traditional CD. On the other hand the laser when reading a DVD that has its tracks closer together must be more precise and with a certain intensity.
Maybe the lasser is failing, this brings 2 potentiometers or adjustments to increase or decrease the power of the lasser, one corresponds to audio discs and the other for dvd, readjust the one of the dvd giving a little gain mark it before moving it, If it does not improve or worse you leave it in the initial position .... greetings.
Regards excuse me I could not answer before I thank you for the possible solutions but neither worked
I keep changing the laser. Thank you for your answers.