Tandy 102 display fault

I managed to scavenge a Tandy 102 earlier today (1988 build, 32K memory). Physically it's in good condition, and powers up, but the display's a bit unwell, having an entire row of dead pixels 4 up from the bottom, and a 32-pixel high column of dead pixels 22 pixels in from the left (on just the lower half of the screen, the upper 32 in that column are OK). The fault seems a little bit more subtle than that, however; sometimes (depending on which app I'm in, and the angle of the screen, and what I type) I can see some garbage in the first two characters (12 pixels) of the dead row - usually much fainter than normal "on" pixels (barely even visible), and occasionally a fully-on pixel, but at the wrong x-offset for whatever I've typed. Question is, where to point the finger? I've no idea how the 102 addresses the screen, although when I was checking it over inside before powering on I noticed all of the HD44102 ICs - are each of these responsible for a small rectangular area, or is the relationship between them and their pixels more complex? Could a fault with one potentially knock out / corrupt an entire display row? Does anyone have a simple BASIC listing for a main memory check? That could be useful (one particular reason for mentioning that is that when I first powered the machine up, it had a non-default date and showed some files present, but in trying to scroll through the contents of one it reset, lost the files, and set the date back to 1900). I already re-seated the cabling between display and the main logic board; the cable itself looks to be in good condition with no signs of severe distress, but I'll check the individual lines with a meter just to be sure. cheers Jules