This forum is dead i think

.. But i still wanna share what ive discovered today. I went to 3 different 2nd hand notebook stores (with my MPC 500) and
tried more than 20 different SD rams (100 mhz to 133 mhz, Hyundai, IBM, Toshiba, Hynix, Kingston, etc. 256-128 even 64 mb rams too) most of the rams does not work with Mpc 500 (OS 1.31) but I could find 3 working rams (IBM, Kingston and Infineon) but only Infineon was 256 Mb and 133 Mhz so I picked that one ( but the identical 2nd Infineon came out from the same laptop did not work which is very interesting).
After you installed a ram and turn the MPC on,
if the "Ram test" starts on its own, probably that ram aint gonna work and the ram test will fail in the 3rd or 4th pass. If it starts normally (like standard 16 mb ram) and says 128 mb (64mb or whatever), installs the songs and plays them (without fail, because with the Kingston 256 133mhz ram it was turning on that way but the screen was freezing after a few minutes) that will work flawlessly. Btw the first Infineon ram i bought is working on laptops though does not work in my mpc 500, here is a picture of the 2nd Infineon ram I bought today (the working one).

Ps: The first Infineon (256 MB 133MHZ CL3 Sodimm 8 chips 32Mx64bit) i bought did not work, besides the working one's identical one did not work either so I can say if a 3rd party ram does not work with your MPC you should try different rams without thinking there may be a problem with your MPC's motherboard, and do not spend more than 20 $ for a 3rd party ram, because even if the technical datas match no1 can guarantee its gonna work.
MPC 500 (128 Mb ram & 2 Gb Cf), Roland Sp-202, Dr-202..