I've had an MVP2 for about 4 months and IMO it's one failing is a center pin that gets pushed down making a poor or non-connection for some
tanks. It's easily remedied though, take a tiny screwdriver, paperclip, toothpick (something small) and stick it down beside the pin and wiggle it gently on all sides as you pull up. When I do this, I usually can't tell if it's lifted up or not but any
tank I try always works and the MVP2 reads Ohms correctly.