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Old 25th August 2011, 07:36 AM   #1
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Default Alpine MRP-F240

Amp powers up and produces both - and + rail.. I get -15 volts on both pins 4 and 8 of all op-amps ..

Amp produces no sound any ideas where to check??
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Old 25th August 2011, 01:34 PM   #2
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I'm assuming that you've checked all switches and pots.

With the black probe on leg 1 of Q504 and the red probe alternately on each end of R516. What is the DC voltage on each end of R516?
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Old 25th August 2011, 05:37 PM   #3
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On both ends i have -2.63 volts
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Old 25th August 2011, 08:24 PM   #4
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Drive a strong signal into the amp. Set the gain to the highest point and set the crossover off.

Which op-amps have signal on their output pins?
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Old 25th August 2011, 09:22 PM   #5
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Non of the op-amps have signal on the output pins
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Old 25th August 2011, 09:37 PM   #6
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Do you have signal on the backs of the RCA jacks and where they solder to the board?
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Old 26th August 2011, 12:40 AM   #7
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Yes
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Old 26th August 2011, 12:49 AM   #8
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At the top of the page, I assumed it was a typo but I may have been mistaken. Do you really have -15v on pin 8 of the op-amps?

If so, you need to find that fault first.

If it was a typo and you have +15 on pin 8, do you have signal on pin 5 of IC101 and IC102?
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Old 26th August 2011, 12:55 AM   #9
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Not a typo its - 15 on both pins 4 and 8
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Old 26th August 2011, 01:21 AM   #10
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Did you attempt to repair the +15v regulator?
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