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Don Allen
 
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Default NAD 7240PE help identify blown up resistor please!

In article ,
says...
Hi

This is not going to be easy without being able to post the picture,
but here it is: my brand old (but awesome) NAD 7240PE blew up
spectacularly the other day - with smoke and all..

If you open the case, you will see 2 big capacitors (80v6800uF, the
biggest of them). Just beside these, towards the front of the device,
there are 2 smaller capacitors (35v330uF). Now, just in front of those
2 capacitors are lined up 2 resistors (color code brown black red
gold), 2 diodes, 2 more resistors (same color code) and one resistor
... ???? Well mine is completely black. CAN SOMEBODY TELL ME THIS
RESISTOR COLOR CODE PLEASE?

Thank you!
yannick

ps any reason for this to blow up anyway?


Yannick,

I have a service manual for the NAD 7240PE, and I am currently looking
at the amplifier PCB parts location graphic. R505 and R511 are both 1K,
but are to the right of C513 - the 330uf@35v. Can you see the silk
screened nomenclature of the resistor in question? Can you also see
transistors Q301 and Q302? If so, where is the resistor in question
located in reference to these two transistors? If we can tie down the
exact location of the resistor, or its nomenclature, I can tell you the
value.

According to my parts location graphic, there aren't any 1K resitors
lined up directly forward of the electrolytic caps. Since NAD uses
contract manufacturing, it is possible that we are looking at two
different production runs, hence different amp PCB layouts. Does your
amplifier PCB have a part number of 1402-500-91?

Please advise, and I will try to help you as much as possible.

Best regards,
Don Allen