HELP - LM337 supply problem

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Hi All,

I am having a problem fault-finding on the PSU in my Arcam Alpha CD 6.

The section is in the picture below.

The input to the LM337 is correct at 27v.

However, the output is only 1.5v.

I have changed the regulator but it is still the same.

The supply goes to the muting relay circuit and to the -ve supply for the opamps.


Any help fault-finding gratefully received.

Andy
 

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PRR

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Joined 2003
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I'm glad you knew; but I'm sure someone will come along not-knowing and become enlightened.

I know the physical reason the pinouts differ (most negative major circuit is die-bottom and is soldered to the heat tab). But it baffles almost everybody first-time.
 
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