Genelec 1031 Driver cards need repair/help

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saint gillis

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I have a doubt with the clip circuit, I guess the idea is that when R17 draws excessive current Q18 start to conduct, and spikes above 1V make the comparator IC2A (schematic hereunder) go down and the "clip" led lights up..
I've put the hole circuit in Spice and the simulation doesn't react as expected for the clip indication
 

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saint gillis

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Here are the 2 schematics side by side for a better global vision :

a5cfd1511f990385cafe212e9e35c6ba.jpg



52579-12a6ae27bcb04401b85f0a5ec69f09ff.data
 

saint gillis

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Now I did some measurements on an original working 1032, and comparisons with the repaired one :

Bass PA frequency response (brown is original, green is repaired) :
PA BASS COMPARE.jpg
Crossover Bass line output response (purple is original, blue is repaired), we can see that the difference doesn't come from the PA, as we have the same mismatch in the crossover (probably the capacitors 5 or 10% tolerances) :CROSSOVER BASS COMPARE.jpg

Treble PA frequency response (purple is original, pink is repaired), crossover line out is the same :PA TREBBLE COMPARE.jpg

Finally I did measurements with a mic in front of the speaker (same place same mic position, 10cm from acoustic center), green is original, red is repaired :
ACOUSTIC MEASURE.jpg

And here the blue graph is the PA Block of the original 1032 mounted on the repaired speakers :ACOUSTIC MEASURE 2.jpg

Feel free to comment.
 

saint gillis

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After checking and repairing other things on the 1032 I was working on, like soft-start muting circuit problems and clipping indication circuit pbms, I did a final calibration (Red is original working one, and Green is the one I've repaired).
So I can now confirm that my retro-engineered boards are 100% efficient !

1673041846914.png
 

Whoops

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After checking and repairing other things on the 1032 I was working on, like soft-start muting circuit problems and clipping indication circuit pbms, I did a final calibration (Red is original working one, and Green is the one I've repaired).
So I can now confirm that my retro-engineered boards are 100% efficient !

View attachment 102625


WOW, Amazing and Impressive work.
First on the circuit tracing, that alone is a lot of work and hard to do with SMD components.
Then you designed your own replacement PCB using proper size components, outstanding.

Frequency response looks Great.


Congratulations
 

gepicaster

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Jan 26, 2020
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Hello everybody ,

a friend ask me help for check a non working Genelec 1031 monitor ,
after some test (as indicated in the service manual)
seem that the problem is on woofer driver card, fitted with smd components ,

any help about how to proceed for right test and repair the card is welcome ,
thanks in advance.
S.
I draw a schematic of the modul, I have here two 1031 with non working bass part. So if you need any help I send it. I appreciate when there is someone who can help me. regards Mike from Munich
 

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saint gillis

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I draw a schematic of the modul, I have here two 1031 with non working bass part. So if you need any help I send it. I appreciate when there is someone who can help me. regards Mike from Munich
Hello Mike, thanks for sharing, I can see few mistakes maybe :
- you have 2 times 3 diodes in series, these are indeed general purpose diodes, all others are 5v1 zeners
- the capacitors on the output transistors are not correctly placed
- few npn transistors are noted pnp and vice versa
 

gepicaster

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Jan 26, 2020
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Thank you.. I´ll check it - it was 2 years ago - since that time these Genelecs are on the shelves, I wish they would run again..
kind regards
 
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