My 77 has been with me for about 30 years, it's a great and rugged meter, mine even survived being slammed against the wall by my ex. Best meter I ever owned!
Rescued from oblivion. Opened the shell and found a AAA battery wedged between the two boards. No idea how to get to it to replace it Anyone can shed some light, or perhaps an instructions manual for this meter. All the manuals I've found only show a battery in series with the resistance probe...