I've got a Compaq Portable (the original model, not a Plus), and it works great, but the screen geometry differs starkly between the high-res text mode and low-res graphics/CGA mode. When I first got it up and running, geometry in text mode was fine, but graphics mode - or pressing Ctrl-Alt-< to get low-res text - leaves the screen somewhat smooshed vertically and offset far enough to the right that a good chunk of the picture is cut off. Once in a great while, CGA mode will display without being shifted off to the right, though I haven't figured out what causes it. If I tap certain parts of the chassis, the screen will often "jump" briefly.
If I adjust the geometry pots, I can get the CGA-mode screen centered and looking pretty good, but then switching back to text mode leaves the picture stretched off the top and bottom, and moved off the left edge! There doesn't seem to be any compromise setting that looks pretty good in either mode. Graphics mode is also quite a bit brighter than high-res text mode.
Does this suggest any particular component failure? I checked continuity of the caps on the video board, and couldn't find any reading as a dead short.
If I adjust the geometry pots, I can get the CGA-mode screen centered and looking pretty good, but then switching back to text mode leaves the picture stretched off the top and bottom, and moved off the left edge! There doesn't seem to be any compromise setting that looks pretty good in either mode. Graphics mode is also quite a bit brighter than high-res text mode.
Does this suggest any particular component failure? I checked continuity of the caps on the video board, and couldn't find any reading as a dead short.
