I found the schematics online. I'd post a link, but it says I'm not allowed, so, if you want to see them, search "sony_playstation_2_scph-70000.pdf".
21 is R9006 1-218-953-81 RES,SMD,1.0K 5% 1/16W 1005, 27 is R9004 1-218-965-81 RES,SMD,10K 5% 1/16W 1005 and 31 is R9025 1-218-961-81 RES,SMD,4.7K...