I love old electronics and recently purchase a Panasonic TR-4CT5, it powers on and volume text is normally bright. Just have issues when I plug line in. Brightness of the input is fine for a minute then fades to super dark.
Volume label stays at right brightness so I figured it;s not the CRT or bri ghtness, feel it's a capacitor somewhere or something to do with the video input as on UHF noise is OK and doesn?t fade dark.
I scoured google for a manual or service manual but I could not find anythi ng. Any help or guidance would be appreciated as I think it?s an electr onic I really want to conserve.