Firstly the way they were soldered in, as I said the previous tech did a fantastic job of ripping out the parts and hacking the paths, the VR's were just hanging on by a blot of solder used to connect the 3 pins to what was left of the signal paths and there was some monkey business with these too. I suspect that they were (and I copied that with the new parts) put in the wrong way around but without a schematic this would be hard to verify.

what do you think?

I tried turning it on, and after a couple of seconds the same thing happens as before, loud noise and the peak light tuns on. Maybe it's the caps that need to be replaces, 2 x 6800uf 63v and while I'm at it I'll change the bridge rectifier out too, what the correct replacement for a PBL403?

thanks
J.

There are 3 of these chip amps:

LM3886 1 - pin 1 is tied to pin 3
LM3886 2 - pin 1 is connected to nothing (pin 5 however is soldered to something)
LM3886 3 - pins 1 and 5 are both connected separately to the board

I haven't tried turning it on yet, but before any replacements the amp was giving me very loud noise and thumps through the speaker and going to protection or peak mode. And also they had used heatsink washers that were too short allowing for the mounting screw to short the amp chip to the heatsink.

I just wanted to be sure before plugging it in.

thanks
J.

Hi folks I'm trying to figure out if this power transistor can have Pin 1 completely left out of the circuit? That is... not soldered to anything? what I have here is an Italian made active stage speaker, it has 3 x LM3886's, 1 x LM317 and 1 x LM337. The LM3886's are all have a different soldering layout. It was severely hacked by the previous "tech", one of the LM3886's had been pulled out by force and he pulled all the paths along with the pins and did a fabulous job of trying to solder everything back in. I've got myself a set of new LM3886's, new LM337 and a new LM317. I have already installed and cleaned up the hacked LM3886, it was even missing one of the pins, I have also installed the LM317 and LM337 and am currently on LM3886 number 2 which has also been messed with but not so badly. The only solder point missing is on pin 1. Holding the circuit board up against the light I can see where the solder point used to be but it doesn't seem to be pathed to anything, just a solder point.

Do you think that this is normal? what would this pin usually be tied to? And yes I have asked for the schematic directly from the techs of the company that makes these speakers, but no luck whatsoever, even if the speaker is no longer made.

Any help at all would be great
thanks
J.