I Need Altec Lansing Multimedia Computer Speaker System Acs90

I bought an ALTEC LANSING MULTIMEDIA COMPUTER SPEAKER SYSTEM ACS90 made in China. They speaker was too god, sounds so well and served me. Later, it developed a little problem which made me take it a technician who burnt one IC inside. I later took it to another man, the man replace two ICs inside as the problem but was never good. So I was asked to go to the best technician in my area, when I went  he asked me to provide the IC numbers the man changed so I was able to provide one remaining the one that starts with LM.

Plz can somebody who has smiliar speaker help me out with the IC number that starts with LM. It is the smaller IC.

To view the speaker's full image http://cgi.ebay.com/Altec-Lansing-ACS90-Stereo-Speakers-with-Subwoofer-out_W0QQitemZ200100545507QQihZ010QQcategoryZ41845QQcmdZViewItem

No help for me here

Plz I have tried all these but could not see what I needed. So if u could help me. I will appreciate it