My main family-room TSU3000 touchscreen wedged up today exactly as described, leaving me with a dead Pronto and a *very* frustrated wife. I pulled it apart and cleaned the connectors and display, with no success. However, doing the needle-to-the-bond-site trick on the ribbon cable's termination on the display did indeed do the trick. Amazing. It's back up and running. I've now swapped it out for one of the less-used Prontos in another (brightly-lit) part of the house...

This is almost certain to be a temporary fix only: the comments about humidity levels affecting the unit are very telling, and poking holes into the previously-hermetic bonds between the polyimide cable and the underlying printed traces on the display will almost certainly lead to their eventual deterioration. Well, I have no problem with that. They were clearly deteriorating in any case, as was the backlight (which is now really too dim to use in the dark). The unit's next stop was the dumpster, so it was worth doing something that is likely to be detrimental to the unit's health. I believe that Philips has a manufacturing process issue with these bonded terminations, and that that's likely to worsen with time on all my units. So, I'd believe that folks can probably expect to see more and more of these issues. The needle hack is a useful tip: thanks to the folks who came up with it.

I've ordered a replacement TSU3000 from the Philips outlet, staving off the inevitable migration to something else for a little bit longer. However, after this, the all-important SAF (Spousal Approval Factor) is in the toilet, so that schedule may yet get changed...