Problems after the RAM upgrade

I bought a new MPC500 and then ordered the 128 Mbyte RAM upgrade online from Thoman in Germany: Akai EXM-128 (Mutec DMC-12) - 128Mb memory expansion for MPC 1000 and MPC 2500.

I installed the card carefully, turned on the MPC500, and I got different error messages and the MPC500 is freezing (can't choose different functions or menus):

"Inv. gen inst. PC (a50089c2" or

"Inv. slot inst. PC(a50089c4)":

I have removed the upgrade, installed the latest OS upgrade from Akai (following Akai's instructions), installed the RAM card again, rebooted and - I have the same problems.

I formatted the Flash card, installed the OS upgrade again, then installed the RAM card again - but the problem is still there. - In one occasion, I was able to start the MPC500 (and it showed the 128 Mbyte in the display), but after playing with it for a few minutes, the same error message showed up. When I remove your RAM card, the MPC500 loads samples and plays perfectly. So, it seems that the RAM card is not the correct one, or it has bad RAM.

I have contacted support at Thoman and Akai (and the Norwegian shop where I bought the MPC500), but there is no response from them...

What do you suggest that I do?

hold erase/undo at power up, if that fails call thomann for an return number and get it replaced, they are pretty good with that and will pay the shipping cost also

phono wrote:hold erase/undo at power up, if that fails call thomann for an return number and get it replaced, they are pretty good with that and will pay the shipping cost also

Thanks for the advice. Holding down rease/undo at power up doesn't fix it. Tried several times. I have contacted support at Thoman three times, and the only thing they respond with it to say that Support has received the mail. Then I hear nothing more...

ring them, mail takes ages