回答“Gameboy Pocket wont boot”I’d recommend cleaning off the pins, both in the cartridge and game boy with isopropyl alcohol. Then check for any damaged or broken pins on both cartridge and game boy as well.
回答“Why do the park light stay on whild driving”I assume you mean your parking brake light. This light also serves as a warning light that your brake fluid is low.
回答“Screen works perfectly for few minutes then becomes garbled.”It sounds like there is an issue with the ribbon cables that attach the plasma display to boards that control that display. If you remove the back panel of your TV you will find two circuit boards with several ribbon cables attached. One board controls the horizontal display the other is for vertical display. These boards may be hiding under speakers or other components but will likely be near the edges of the TV. I would unplug and re-plug in all the cable to check that they haven’t come loose over time. If they are damaged you will have to source replacement parts.