Memory Cards not working

I just recieved a broken dreamcast from a friend, it was a simple fix, replacing the f1 resistor, but i have encountered a new problem. When i put in my vmu, it will not stop beeping for a long time and when it does the controller will not function. I performed the AA battery mod on the vmu and it works flawlessly by itself so i cant, for the life of me, understand what the problem is. I have another memory card, just a straight card not a vmu and when i put it in, the DC cannot detect it, the controller functions but nothing can be saved. I had my friend try the cards on his DC and he says that they work fine. Im going crazy without being able to save my tony hawk game!! Any help will be greatly appreciated.

really obvious; but have you tried a differant controller?

try to figure out where the problem is swap the controller ports on the dodgy one with one you know works, see if its the same problem, at least then you know if its the controller board or something else.

We had a looooooooooong discussion about f1 on a french board, it seems to be a fuse, not a resistor, if you soldered a resistor it may prevent enough current to flow to the controller to allow a vmu to work with a controller.

theres a tutorial on devcast.dcemulation.com that says the resistor you replaced the fuse with should be no more than 10 ohms as then not enough current gets through, perhaps you should try a smaller resistor?

try clear the comtroller, may 8be can fuction 8) 8) 8) 8) 8) 8) 8)

I have almost the excact same problem, I can play with my 1st party dreamcast controller and vmu but when I put my 3rd party controller in slot 2. The controller port doesnt detect anything at all. I mean the controllers fail to work at all it says please insert controllers.

This is after I replaced the resistor just as you did as well. Ive yet to solve this problem and I really have no idea what to do. But its probally your controllers by the way and not the memory cards at all.