Are you positive that's "1856/18" and not "1056/10"? The default font for Amigas use a slashed zero.
If it is, then you've got a Supra (Manu # 1056) RAM (Prod # 10) board in there. It'll be a full-length Zorro-II board, with either a couple of rows of chips, or an entire armada of 'em. The most common problems with this guy:
Bad RAM -> This board uses 1Mx1 DRAMs, set for banks of 2M (0MB, 2MB, 4MB, 6MB, or 8MB). A fully populated board will have 64 chips (plus logic/buffers). You'll need to set the jumper to "Test" mode and run the Supra RAM Test program to ID the bad chip (it'll tell you the column/row of the culprit).
Jumper mis-set -> Setting the jumper to 4MB when you only have 2MB won't work. Count the rows of chips to get the MB count, and set the jumpers accordingly.
Gunk -> Sometimes, just re-seating the card will clean up any corrosion or gunk on the contacts. Can't hurt.
Conflict -> Do you have any cards (like a BridgeBoard) that are also mapped into the 8MB auto-config area? If so, set the Supra to 6MB or less to have it auto-map the RAM around the other board to check.
Check those, and get back to us
banzai
