According to the User Manual (see page 117), the camera came with an "MMC-16M" card and can additionally use "SDC-128M" or "SDC-512MSH" cards. From some searching, I have only found off-brand cards on Amazon. B&H Photo doesn't carry these cards at all.
So even though I state to always avoid Amazon for memory card purchases, in this specific case, due to the age of the card technology, see if you can get a replacement card and try it out.
Note that your camera has been retired by Canon, so if you're dealing with a hardware issue, they will no longer repair it. May also be difficult to find any camera repair shop that would still be repairing these.