Soundcraft Compact 10

[revbobuk]

Folks - the internal voltage regulator chip on my Compact 10 has blown up. I'm waiting for Soundcraft to get back from their hols; does anyone have a schematic for one of these that I could use to do the repair? The chip failed catastrophically, and has burned off all the markings; I think it's a standard 15V regulator, but can't be sure. And it's taken out a little bit of track too - not beyond my abilities to repair, but anyone who has one could provide much needed information!

 

I think it failed from being on too long continuously - with no power switch, it was easiest just to leave it powered up. Won't do that again.

 

I considered (briefly) buying the service manual from Soundcraft, but at over £50, for a sub £100 mixer - I don't think so.

 

Sorry if this seems trivial, but any help would be appreciated. And yes, I know there are hundreds of screws to remove before you can get inside! :up:

[7thheaven]

Hi, found this forum because my compact10 just burned up this week too. Soundcraft tech service was friendly enough to offer me to send it in for 130 pounds or buy the tech manual.

If you havent ever gotten your question answered, the part in question is labeled P24NF10. Mine overheated and cracked but the labeling is still readable.

 

I think also what looks like a mini transformer just below it has burned up from this incident as well, but I have no idea what this part is. Maybe any info you've gleaned in this half year might help me?

 

best

[Chris Beesley]

http://cpc.farnell.com/stmicroelectronics/...020?Ntt=P24NF10 :P

[revbobuk]

Hi, found this forum because my compact10 just burned up this week too. Soundcraft tech service was friendly enough to offer me to send it in for 130 pounds or buy the tech manual.

If you havent ever gotten your question answered, the part in question is labeled P24NF10. Mine overheated and cracked but the labeling is still readable.

 

I think also what looks like a mini transformer just below it has burned up from this incident as well, but I have no idea what this part is. Maybe any info you've gleaned in this half year might help me?

 

best

 

Thanks for that - yes, the part is an FET rather than a regulator; I've managed to get one. And I really ought to finish the job. Here's what the board looks like:

 

http://lh5.ggpht.com/_wyAmW2s5NFY/SyKD-u-MwfI/AAAAAAAAEYc/wAXBNqWGo1I/s800/IMG_2529.JPG

 

http://lh5.ggpht.com/_wyAmW2s5NFY/SyKEATI9PaI/AAAAAAAAEYk/hcxe90kAE5M/s800/IMG_2530.JPG

 

I would like to confirm where the PCB traces went before I repair!

[7thheaven]

So that yellowish square beneath the FET is what I need now. My "Accident" burned out both of them. Any idea what that is? The tech guy I contacted wouldn't give me any info, just a link to order the tech manual.

@Beasley, yeah thanks it seems to be relatively easy to find online. I'm in Germany so I'll be ordering from Mouser.

[Brian]

The Compact 10 runs on a 12v DC external supply. Being an audio unit it's going to need a -ve rail from somewhere and I'd guess that the burned out FET along with the 'yellowish square', which is a transformer, is used to generate that rail. The transformer is not going to be easy to find a replacement for. It'll either be a custom wound unit or any one of a number of choices from obscure suppliers. Without any identifying marks you'll not get one.

 

As a 'kill or cure' repair it would be possible to use an external supply which gives both +ve and -ve rails but without a unit in front of me it's impossible to say what you need to do.

[KevinE]

Yep agreed with Brian, this is a switching regulator. The little mishap may have taken some of the SMT out as well which means an amateur repair may be an expensive exercise!

 

The switchmode transformer will be a special and available only through Soundcraft or their dealers.

 

You'll also need to cut out that charring because it may be slightly conductive, which, although not at mains voltage, will eventually gnaw away at the reliability of the circuit.

 

 

PS I've just noticed with a wry smile that label on the pcb 'Caution Hot'.

 

:P

[Asaph62]

First timer here. This thread helped me with my problem so I thought I'd share my experience.

 

I was sitting at my desk about a week ago and suddenly noticed the tell-tale smell of burning electronics. Sure enough, right next to me was a small column of smoke coming from my Compact 10. I immediately pulled the power but the board was already dead.

 

After taking everything apart I saw the source of the smoke was the FET in the power supply. The small yellow transformer had a little brownish tint on the top similar to the pic posted by revbobuk, but didn't seem to me to have any other signs of overheating. Also the big cap next to the FET looked a bit swollen. After reading this thread I decided to order the FET and 100u cap and give it a shot. My FET was marked IRF540 which I guess is the same as the P24NF10.

 

Got the parts yesterday and replaced the toasted ones, everything now works fine.

 

From now on, I reckon I'll be unplugging the power supply before I leave for the day...