Genelec 1031 Driver cards need repair/help

[scott2000]

If you have a working card, you could always compare readings at various points???

I also know some Mackie plate  amps had issues with the giant 5 watt resistors cracking at the solder joints too.....


Good luck!!

 

[mrclunk]

Repaired a 1032 a few years ago that had an issue with the bass power amp. It's a very similar circuit.
From memory it was C7 at fault, even tho it looked ok on the meter. Yellow tant. Check T6 next to it too. Worth a punt...

 

[Whoops]

I have some 1030 to fix also, time to do so

 

[philly]

Hi All,
Just came across your website which looks like a world of information. Hope I am posting in the correct area and not jumping in where I shouldn't. 
I repaired some Genelec  1031 for a friend recently which had the usual 'dry joints' and o/p transistors faulty. One unit was returned from my friend as it gives a loud 'thump' during switch on only. My volt meter across the speaker confirmed dc present during switch on.  Unit works 100% afterwards but I am afraid of this popping the speaker if not taken care of now.  Any suggestions. I removed the original plug and socket arrangement on this unit as they were causing intermittent problems before. I now have the driver boards soldered directly to the main pcb. Any help or suggestions appreciated.

 

[scott2000]

These have a muting circuit? Maybe something hokey in there????

 

[philly]

thanks scott2000,
I plan to get back to the problem this week. I think I have a full schematic for this unit.  The mute circuit is one avenue for me to look into. Keep you posted.

 

[fazer]

Mute circuit as Scott2000 says is one place but , Also the amps need biased/offset correctly.  They are direct coupled so dc can pass through if the offset before the power amp is set incorrectly.

 

[Whoops]

I have some 1030 to fix also, time to do so

I fixed my 1030, there was  blown SMD electrolytic capacitor.

It was easy to spot visually, I replaced it with a normal size 105degrees electrolytic capacitor of the same value (used higher voltage) and it's working great again

 

[philly]

Hi All,
Set the biased/offset as Whoops suggested seems to have cured the problem. 
Thanks all for your help.

 

[SIXTYNINER]

These have a muting circuit? Maybe something hokey in there????

thanks so much for any post !
please scott2000 image link seem broken ,
possible a working link about ?
more thanks

 

[scott2000]

Weird..... Just updated post but it's in the service manual too....I just singled out that section

 

[anotherfuzz]

Hi, I've a 1031A with a PA-Driver problem.

I've to replace an SMD transistor (orange circle in picture).

Anyone have information about this transistor model?



Thanks a lot

 

[moamps]

It's NPN type, same sa others on your PCB with letters D and C with small arrow.
https://www.sos.sk/pdf/SMD_Catalog.pdf

 

[anotherfuzz]

It's NPN type, same sa others on your PCB with letters D and C with small arrow.
https://www.sos.sk/pdf/SMD_Catalog.pdf

Hi moamps, thanks for the reply.

The code of the transistor seems to be "DG".
Could it be a BCW68G pnp?

 

[moamps]

It's NPN for sure.

 

[anotherfuzz]

It's NPN for sure.

Ok perfect!
Which could be a proper replacement?

 

[Whoops]

Ok perfect!
Which could be a proper replacement?

Do you have the service manual?
You have a list of the transistors used there, plus schematics and pcbs layout.
you can download it here:

https://elektrotanya.com/genelec_1031-a_monitoring_speaker_amp_1991_sm.pdf/download.html

 

[anotherfuzz]

Do you have the service manual?
You have a list of the transistors used there, plus schematics and pcbs layout.
you can download it here:

https://elektrotanya.com/genelec_1031-a_monitoring_speaker_amp_1991_sm.pdf/download.html

I've the SM.
But unfortunatelly the PA-Driver circuit are not reported and suggested to replace the complete board.

 

[moamps]

Which could be a proper replacement?

I don't know, but maybe 2N4401 or MPSA05,06, or 42 SMD equivalents can work, depending of amplifier's power supply voltage.

 

[saint gillis]

Hello, I have the problem on a 1032 speaker, I think it is the same amp and driver

Here's my contribution to the diy cause :

There might be mistakes, this requires a damn concentration..