@vighneshrath check for a trim pot on the laser assembly. On a laser you do not really adjust the voltages but the resistance. You need to know what it is before you start changing values, otherwise you are going to burn out your laser. So, look for a trim pot on the laser flex to board VC483, also check that board. Adjusting lasers is usually not a lasting fix. Personally, I would replace the laser since that would be the safer alternative. Here is the guide for that [guide|61301].
Now, if you want to further work on the laser diode etc. download the SM level 2 and 3 from this page [[Topic:Sony DCR-DVD 108]] right under the Document heading.