I guess your 90k-Model is incompatible with mc-upgrades.
Does the logo show up, or directly boot to the original OSD?
I assume, you (currently) have no way to run homebrew on this 90k-Slim.
If you have one, a bios-dump would be useful.
PS2 V7/DMS3 V2 (FW:2.4b7); Seagate Baracuda 200GB
PS2 V7/CC1.0 (FW:34 hacked v2 BM:2.1.6); Maxtor DiamondMAX9 PLUS 160GB
PS2 SCPH-30004R; NoMod+NoLaser
3xSony MC 8MB
MAX/Datel 16MB with Boot-CD
Custom FMCB 1.8b+ Beta-Build, my AIO 0.5, Sony&xRhino-Linux