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QUESTION: Yamaha MX-1000 Power Amplifier Problem

I recently acquired a used Yamaha MX-1000 Power Amplifier that was VERY dirty.

I opened it up and found probably 3 cats' worth of fur covering the components inside. You could barely identify the various capacitors, resistors, etc.

I am no stranger to cleaning out dirty audio gear, and so I took my trusty Hoover and **CAREFULLY** vacuumed out all of the fuzz and lint I could see. I also used a small paintbrush as a miniature whisk broom to get in the tighter areas.

I was very, VERY careful not to disturb any wiring connections.

I carefully put the top cover back on and used the amplifier for a couple of days with no problems whatsoever.

But now I have noticed that the digital wattage readout on the front of the amp no longer lights up. I believe that it DID light up normally after I re-assembled the amplifier, but I still can't help wondering if I did something to break a connection somewhere.

Does anyone have a schematic for this amplifier? It's really not a very important feature, but it bothers me that it no longer works.

Is this a common problem on these amplifiers?

Any assistance will be GREATLY appreciated! Thanks in advance..........

(I also posted this to rec.audio.tech, not knowing which newsgroup was more appropriate....my apologies......)

Reply to
EADGBE
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You can buy a service manual for your unit from

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$15.00 for a download, $16.99 for a paper copy.

--
Dave M
MasonDG44 at comcast dot net  (Just substitute the appropriate characters in the 
address)

Experience: What you get when you don\'t get what you want
Reply to
DaveM

It's very hard to say, if the unit has been sitting around for a long time, it's possible you operating it may have kicked out a bad cap that just was aged, and the minor heat you were generating did it in.

I don't know what type of display you have how ever, if it's a fluorescent display, you may have a bad electrolytic cap in the inverter section that supplies the HV low current for the display..

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Reply to
Jamie

The power meters are the liquid crystal type; however, the digital wattage readout (which is the part that doesn't work), seems to be your standard LED digital readout.

Reply to
EADGBE

You may have stand alone panel module meters. You need to check the connections going to them and power supply. At min, they should be displaying "0"

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Reply to
Jamie

You are exactly right. When they were working, they would read "0.0" whenever the amp was idle.

Reply to
EADGBE

My guess is that I will have to check the common-cathode connection for the LED digital display, to see if everything is OK there. I will also do the customary power supply check, to make sure that the circuit is even getting any power to begin with.

Reply to
EADGBE

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