Talking to a VAX4000/300

Greetings all; I picked up a VAX4000 last week and have been trying to get talking with it. I found a general VAX4000 series guide which says the terminal settings should be 8N1 and I've got the speed right between the dial on the front of the VAX module and the VT240 I'm using. I get partial data, with ?s scattered all over the place. Frequently it loses carriage returns and things get stuck scrolling off the side of the screen. What am I missing here? Is it not 8N1? I've tried flipping it around to 7N1, 7E1, etc, but usually that just results in absolute gibberish, the 8N1 provides the best signal-to-noise ratio. I'd appreciate any thoughts given. Elsewise, I'm pretty pumped. I have another 4000/300, but it has a bad PSU. I figured I'd put the two together to get the nicest working machine, store the spare PCBs and dump the chassis (anyone want an empty 4000/300?). The unit is complaining about some memory errors (came with four memory boards), but with all the crap coming up on the screen, I'm not entirely positive what it's complaining about since I can only read a partial output... Thanks again; - JP