ST701 - possible "meter" fix.
I've been using two of the tiny hearing aid batteries stacked on top of each other with a small rubber washer around each of them to "hold them in place" inside the battery compartment. After sitting idle for perhaps 25 years, it finally came back to life.
My 701 meter went right to the top and stayed there. After much cycling with the aperture ring and shutter speeds - still no joy - until I finally "flipped" my batteries.
I'm on my second set of batteries now in about a year. I'm using size 312 and the rubber washers were procured from Lowes that came in a blister pack of 25. My experience is that after a fresh insert, it takes a few minutes before these hearing aid batteries "come to life."
My 701 now meters well enough that I had the confidence to shoot a few rolls of E-6 and they all were nicely exposed.