Tektronix 4014-1 troubleshooting advice

Hi all -- Picked up a Tektronix 4014-1 terminal. It's in pretty good shape, nice and clean and it's in nearly-working condition except that the storage behavior isn't quite right. On power-up, write-through doesn't. (That is, characters don't get stored to the tube.) Clearing the display via the RESET/PAGE key clears a roughly elliptical region in the center of the display but leaves the outer edges a mess. The cleared region stores characters properly. You can see the overall effect here: http://yahozna.dyndns.org/scratch/tek4014/clear.jpg After a 2-3 minutes of warming up the area cleared by RESET/PAGE increases. I haven't run the terminal long enough to see if it eventually completely erases the screen (while the power supply appears to be within tolerances, I still need to rebuild/reform it so I'm not going to run it too long yet). So far everything else seems to be functioning properly, the cursor appears properly (and does not write through), input is accepted from the keyboard, etc. I've been reading through the service manual on Bitsavers and it describes a very in-depth alignment procedure which I'm prepared to go through (once I've got the power supplies rebuilt) but I thought I'd ask here if this problem rings any bells and if there's anything I should immediately suspect or adjust. You guys know everything :). Thanks as always for the advice, Josh