I have a Yashica CS-201 falsh attachment on a Yashica FX-70. I put all new batteries in it and cannot get a "flash ready" symbol nor will the test light go on. What is the likely problem?
The most likely cause is dirty battery contacts, use a pencil eraser to clean them, then vacuum debris out. The second most likely cause is a loose wire to the battery contacts, which would need resoldering.