That trim is a pain in the you-know-what because its retaining tangs fall off as you look at them. It protects the connections to the display, however, so it is worthwhile to invent a couple of circular clamp bands to keep it in place.

While it is busy falling off, however, is a good time for you to check the connections to the display, which, from the symptoms that you mention, need attention. A thorough examination will involve an almost complete demolition of the PB, which you may as well get over and done this early in your mutual acquaintance.

The demolition will enable you to replace the backup battery inside, if that is needed. (Backup batteries—in PBs they do more than just keep PRAM settings—don't begin to recharge before the main battery is near full terminal voltage, not capacity.) This means that even with a main battery that has very little capacity you can get the backup charged just by leaving the AC adapter attached for a few days. If the main battery tries to imitate a toaster during this process, stop the charging, because the battery has too many internal shorts to be of any use.

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