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Genelec 8020B repair

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As there seems to be a good number of Genelec fans on this forum, I figured it would be the right place to document my repair attempt of some Genelec 8020B speaker.

I recently got 2 speakers: one of them has a weak woofer/bass output and a lower overall volume. The previous owner informed me that the repair shop for Genelec products in Switzerland had closed and that it would not be cost effective to send the speaker to Germany. I tried to contact Genelec for some tips about repairability but I received a very generic answer. In my opinion old school companies were doing a better job before sustainability was even a trend. Lenco were printing service schematics right into their turntables and Studer/Revox are still selling parts for very old products.

The lack of service instructions and parts should not stop us though and we will take this opportunity to learn a thing or two about monitor design and electronics.

Part 1 - disassembly​

1.jpg

  • Remove the following screws from the back of the speaker:
    • Four long Torx screws
    • Two Philips screws

2.JPG

  • Remove the following screws from the controls:
    • Four Torx screws
    • Three self-tapping Torx screws
  • Remove the two metal covering pieces. It may take some fiddling to remove the bottom one.

3.jpg


  • Remove the Torx screw grounding the chassis. Do not forget it. THIS IS THE SCREW YOU WILL FORGET TO REMOVE AND TO PUT BACK! ;)
  • Take the two halves of the speaker apart. It will look take some force as the plastic joint making the enclosure air-tight is adding some friction. Separate preferably the right side first, in order not to put any strain on the cables inside.


4.jpg


  • Remove the two white foam pieces.


5.jpg


  • Remove the three Torx screws holding the bass port in place.
  • Remove the bass port.


6.jpg


  • Unplug the following connectors:
    • Unplug the left connector going to the woofer, tweeter, LED and buttons.
    • Unplug the right connector going to the transformer by pressing on its locking tab.


7.JPG


  • Remove the five Torx screws holding the circuit board.
  • Slightly unscrew the Torx screw pressing against the audio amplifier chip. You need a long Torx screwdriver for this. If you do not do this step, it will be hard to pull the circuit board as some metal piece is pressing hard against one component.


8.jpg


  • We are in! We see:
    • Some power circuitry on the bottom and on the left
    • A stereo amplifier LM1876T in the middle
    • Some NE5532 and TL072 opamps on the right
    • Some unknown transistors (M1W?)

In the next part, we will try to understand what all of these components do and find the root cause of the problem.
 
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srrxr71

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I have an 8010 with issues. I suspect it may be a fuse. This will be helpful. Of course I can send them to Massachusetts but if it just a fuse I’d rather repair them myself.
 

YSC

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just wonder, how long did both speakers serviced before dying?
 
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D
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I have an 8010 with issues. I suspect it may be a fuse. This will be helpful. Of course I can send them to Massachusetts but if it just a fuse I’d rather repair them myself.
To check if it's the fuse without disassembling it, you can disconnect all power (!), put the power switch to the ON position and check the resistance between the positive and negative power pins with a multimeter. If you get an infinite resistance (OL), the fuse is probably blown. If you get some resistance that start at 0 ohm and quickly gets to 100-150 ohm, you are loading the capacitor behind the fuse which means that the fuse is not blown and you have another problem. Good luck. ;)

Note that the Genelec 8010A does not have any visible screws. I guess that there is a single screw centered behind the word "WARNING" of the label.
just wonder, how long did both speakers serviced before dying?
My Genelec 8020B have written "May 12" on them, so I guess they were used for 10 years.
 

YSC

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To check if it's the fuse without disassembling it, you can disconnect all power (!), put the power switch to the ON position and check the resistance between the positive and negative power pins with a multimeter. If you get an infinite resistance (OL), the fuse is probably blown. If you get some resistance that start at 0 ohm and quickly gets to 100-150 ohm, you are loading the capacitor behind the fuse which means that the fuse is not blown and you have another problem. Good luck. ;)

Note that the Genelec 8010A does not have any visible screws. I guess that there is a single screw centered behind the word "WARNING" of the label.

My Genelec 8020B have written "May 12" on them, so I guess they were used for 10 years.
ok, 10 years is a fair life time for electronics IMO, though personally I hope mine would last longer
 

srrxr71

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just wonder, how long did both speakers serviced before dying?
So I used them for about 2-3 years. I think it was my fault. I turned the volume up really high and they suddenly stopped. That’s why I think it’s a fuse issue.

I thought the protection would protect them.

Hard to say what happened but I feel like some protective measure was activated and a fuse change or some kind of reset should get them working again.

It was sudden and I didn’t smell burning.
 
Last edited:

srrxr71

Addicted to Fun and Learning
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Joined
Jul 4, 2020
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956
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To check if it's the fuse without disassembling it, you can disconnect all power (!), put the power switch to the ON position and check the resistance between the positive and negative power pins with a multimeter. If you get an infinite resistance (OL), the fuse is probably blown. If you get some resistance that start at 0 ohm and quickly gets to 100-150 ohm, you are loading the capacitor behind the fuse which means that the fuse is not blown and you have another problem. Good luck. ;)

Note that the Genelec 8010A does not have any visible screws. I guess that there is a single screw centered behind the word "WARNING" of the label.

My Genelec 8020B have written "May 12" on them, so I guess they were used for 10 years.
Thank you. I’ll try that over the weekend.
 
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