Sound doesn't work out of speaker. Works through headphones. Crackling sound from speakers when not using headphones. Recap?

The PowerBook 140 was the mid-range of Apple's original 1991 PowerBook lineup — a 16 MHz 68030 with a passive-matrix display, positioned between the Sony-designed 100 and the premium 170 with its active-matrix screen. It established the PowerBook form factor that competitors scrambled to copy: trackball centered below the keyboard, wide palm rest, portrait-oriented display.

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