Datasheet for the LM337, an adjustable three-terminal negative voltage regulator, the counterpart of the positive LM317. The 216 KB PDF covers pinout, output adjustment with two resistors, current limit, thermal protection and typical circuits. In repair it helps calculate the expected output from the resistor divider and identify the adjust, input and output pins, which are arranged differently from the LM317. Check the package and full marking on the board before measuring, since swapping it for a positive regulator will not work.
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