I've made rather good experience with these yellow china cards from DX when they're 32MB or smaller. Better get two and send both to the installer, so if one doesn't work theres a good chance the second does. Best way would be to get some better 3rd party MCs like MaxMemory/Datel or even a genuine 8MB Sony.
Originally Posted by Mithie
Slim PS2 SCPH-70004 (v13) w/ FMCB, 3x Sony 8MB, 1x MaxMemory 16MB (Backup card)
I'm not available for FMCB installation service until I can guarantee a processing time of a few days again, sorry.