Video Ram Error

I have a neo geo MVS 4-slot machine. When I bought it, it displayed “Video Ram Error”. I removed the old chips, soldered in brackets and then plugged in two new, identical chips (Sony CXK5814P35L). These chips were the same as what was already in the machine. Now the machine displays the same message, but the there is a different read and write address for this error. If I remove one chip or the other, the address continues to change each time.

Could anyone please offer me some advice? I am a complete amateur and am totally lost.

Thanks