I have a slim PS2 - SCPH 70006 (a modified one) I bought few months
back and been using the "backup disc" for few months including dragon
ball and winning eleven.

Alll of a sudden, it cannot read disc. I took to the repairman, and he
said that the optical head aging and not have enough light. He replaced
the head. It "worked" again.

BUT , I could not really play the Dragon Ball disc as before. In the
last 20 tries, I can play 3-4 times only, other all "unable to read
disc". For the other like Winning Eleven, it is noraml.

I am trying to fix it. BUT... few question I cannot answer.

If during the first failure, it is really due to the aging optical
head, why it broke down so sudden. As the repairman said the light is
not strong enough. I expect I should experience some problems before it
became faulty. It was really a sudden thing when I became fautly, no
previous malfunction at all.

The second thing is that why it can read the "backup" Dragon Ball from
time to time initially. But now it basically cannot read it at all for
the most recent last trials.

Any master can answer my questions ??!!

JBH-HK