Ld systems pm12-2 powered mixer amp problem - please help.

[NIXX]

can anyone help?

We use 2 minidisk players and two mikes into this mixer ( see thread title) everything normal then in the middle of a song, it just stopped working.

There was no signal apparently going in from the mini disk players, mikes would,nt work,
nothing worked.

The power light still came on and everything lit up as per normal but there was no led indication of any input signal from anything and no output at speakers or headphones.

Basically, we were using this and it made a high squeal and stopped!! very embarrassing at a gig!!

Any help would be great, we cant find any articles on troubleshooting with this mixer and we are booked up for a lot of work so we are panicking. Any advice appreciated.

Nixx.

[Enzo]

I don't know the mixer in question, but I approach any powered mixer the same way.

When you turn it on, is ther any little pop or thump in the speakers to show any sign of life? Inside, have internal fuses blown anywhere?

You need to isolate the problem. Has the internal power supply failed? Has teh power amp failed? Or has the preamp (mixer section) failed?

[NIXX]

Hi Enzo
Thank you for your reply.

Reading what you have posted have isolated to mixer section.

[rdelaplaza]

Sun sx8350

This powered mixer has problems with the internal connections, it uses a sort of flat cable that plugs into slot connectors to connect the signal from the front board to the rear board, those connectors get corroded and star doing all sorts of nasty intermitent things, I replaced those flat cables with independent soldered wires, removing all the flat cable connectors and that took care of a lot of problems.
Other thing that fails is : the plugs in the front, have a disconnect, (like the headhpone plug that disconnects the speakers in a portable radio). and those get corroded.

The 1/4" preamp out in the front (Main Out) disconnects the preamp from the power amp when you plug something, so try a 1/4" plug jumper cable between the (main Out) and the (Power amp IN). ti may fix the problem.
If thats the case you may replace the jacks, or plug/unplug several times so the little corrosion goes away, it may work. Goog luck.