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Old 22nd May 2011, 06:02 AM   #1
diyAudio Member
Join Date: May 2011
Default Nakamichi PA-7 protection circuit

Hi all
I've seen a Nakamichi PA-7 mark I for sale. I would like to know if the
factory upgrade for the protection circuit was already done. How can I
(visually) check that?
Regards from Switzerland
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Old 23rd August 2012, 04:16 PM   #2
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Join Date: Aug 2006
Default PA-7 Protect Circuit Upgrade Identification

Andy, If the upgrade has been done, there is a very small 3-leg circuit board attached to the rear of the main board. Two transistors Q241 &I Q242 + R266, R267 & R268 (Right channel part numbers). The L-channel is identical. There are also 3 wires connected to other added components on rear offer main board.
If it ain't broke, don't fix it!
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Old 23rd August 2012, 04:46 PM   #3
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Join Date: May 2011
Default Thanks

Hi Roger
thank you very much! Very helpful.
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Old 21st March 2016, 01:12 PM   #4
diyAudio Member
Join Date: Dec 2013
Anyone got schematic for this modification or even the service bulletin for this?

It is not present in the service manual I have.
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