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Marantz Model 140 peak lights coming on.

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Big Vandies!! Mwahahah...
The peak lights on my 140 are lighting up at about 0.5 watts. I am going to check the DC offset and the Bias (once I can find a service manual) later today. Any other things I should look for?

This thing has lived and abused life as a DJ amp before I got it.
 
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DC at the output(s) is independant of gain. I would check to see if you lost either the PNP or NPN on the output transistors.

Ron
 
jblmar said:
DC at the output(s) is independant of gain. I would check to see if you lost either the PNP or NPN on the output transistors.

Ron
Click to expand...

The who or the what? I am sorry, but I am not well versed in electronics (although I am not afraid to try and fix them anyway).
 
I had this problem with my 140, it acted just like this on one channel and took me a while to find the problem.
With my 140 it ended up being a pinched wire at the back/bottem that was grounding one of the positive speaker leads from the relay board to the back of the speaker connection jacks. When I removed the back of the amp and moved it away, the problem resolved itself, but when I put the back on, it was back.
What you may want to do is check for continuity/low resistance between the positive speaker connections and ground with a DVM with the unit unplugged!
I rerouted the wire, and use this wonderful amp every day!
Chuck
 
gch53 said:
I had this problem with my 140, it acted just like this on one channel and took me a while to find the problem.
With my 140 it ended up being a pinched wire at the back/bottem that was grounding one of the positive speaker leads from the relay board to the back of the speaker connection jacks. When I removed the back of the amp and moved it away, the problem resolved itself, but when I put the back on, it was back.
What you may want to do is check for continuity/low resistance between the positive speaker connections and ground with a DVM with the unit unplugged!
I rerouted the wire, and use this wonderful amp every day!
Chuck
Click to expand...

I will have to check that, this amp has had 1/4" speaker outputs added to the back (kind of a hack job). They might be causeing this problem.
 
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