PS2 making "clicking" sounds when reading PSOne/Audio CD - 79010

My modded PS2 slim SCPH 79010 (with original Matrix infinity chip) makes some "clicking" sounds when reading PSOne discs, originals and backups, sometimes I have to turn on Diagnosis to make them work... what could it possibly be, is it an easy adjust (like calibrating the laser or something)? Bear in mind that I have no experience in console maintenance.

Thanks in advance!

 

Clean laser and\or adjust the value of cd trimmer on optical drive

 

I'll try that. Do you have any tutorial or something?

 

Here's ones:
http://www.ps2parts.com/laser_adjustment.html

Remember! never go below 800 OHMS! or your laser will burn and die

 

I messed around the videogame a little bit but the PS2 Slim laser works on 800-1000 Ohm, not much room for adjusting... by the way now only PSOne backups don't work, so I won't bother with it, since original PSOne discs are read without problems.

Thanks for the help