Laser or modchip problem?

[whokilledcyrus]

i have this ps2 ver4 w/ a messiah pro 2 installed. before i use to play cd-r games and i was able to use ARmax, codebreaker, and GS disc but now i can't. is it my laser or my modchip that is giving me problems? i tried using a cd/dvd cleaner but that didn't do much. fyi, i can still play dvd games w/ ritek dvd-r's. i've tried different brands of cd-r media(i.e memorex black cdr and verbatim cdr multi-use) and that didn't work. if it's my laser, where may i purchase one at? i appreciate your response.