Have a 512k that was giving error code indicating bad ram.

After changing the ram, get a nice bong and question mark. When floppy is inserted, the welcome to macintosh screen shows, but then the screen flickers and the floppy drive chugs like it can't finish reading.

It does the same thing when a known working external drive is used to try and boot.

Tried another boot disk and the same thing happens. Replaced the Bourns filter for the floppy drive and still no fix.

Any suggestions?