Behringer SL2442FX-PRO > Trouble shooting Main Outputs....

[Twistedpair]

I did more checks in the master section and here the results so far. SUBS 1-4 working, MAIN OUT L-R working, MONO working (Note:see last post), HEADPHONES working, AUX SENDS 1-2 working, TALKBACK working, MAIN INSERTS L-R working. I haven't went back and checked IC34 yet for the low volume on the low pass filter. Thought I would run a few checks first before pulling the lower panel back off.

[Enzo]

Well, I suspect it will go a lot easier with your schematic to look at, rather than me trying to describe the circuit.

[Twistedpair]

Enzo, you have made this repair possible, and have gotten me this far, so please, any description would be appreciated. Even though I have the schematics, interpreting them is another ball game in itself. As I metioned earlier in my post, IC34 previously checked ok before the two new op-amps IC39 and IC44 were put in, but I haven't re-checked it again. In the event that IC34 checks ok on the next check, any idea what would cause the low pass filter, on the mono channel, to go low in volume when it's engaged for the sub woofer frequency ? Thanks again for all your help....

[Enzo]

Not really, it is a small circuit, the first suspect in any of these circuits will be the IC, but after that, I don;t know, the controls are probably the next most failure prone parts.

I mean apparently IC34a works because when the feature is off, the signal comes through it OK. So that leaves IC34b, the dual control, four resistors and a couple caps. Oh, and the switch, ohm out the switch too. Obviously any part can fail, the caps would be way last on my list, the resistors seem pretty reliable, leaving the IC, the control, and the switch. And of course the traces between them. Scope pin 7, got signal? If yes, then the switch looks bad. None? Then control, etc.

[Twistedpair]

Enzo, I finnally got around to replacing IC34 and it seems to be working again. I'm going back to re-check everything on the mixer to make sure that all is ok. I want to thank you once again for all your help. This repair would have not been possible without you and I learned a lot just because of your help.

Thanks, Twistedpair....

[jaceywendel]

I don't understand. The insert is an in. How does it work with the main outputs.

[Enzo]

An "insert" and an FX loop are the exact same thing. Only difference is that the insert does it in one jack. It has tip and ring contacts, and I can never recall which was send and which was return. In any case, if the return side gets a fouled contact surface, you get no through signal.

So the Inset is both in and out. One contect of its "stereo" connection is the output of the basic mic preamp, the other contact is the return input for the mic signal to continue its voyage.

[renz]

behringer sl2442fx-pro eurodesk effect display is blinking light what possible problem ic34,39,44 is already replace but same problem

[renz]

sl2442fx-pro behringer effect no display somtimes bliking or flushin light ic 34,39,44 are all ready replace but same problem.any body help for my behringer sl2442fx good bless

[renz]

enzo please help my behringer sl2442fx-pro eurodesk effect is blinking light and led meter also blinking the sound is no problem ic 34,39,44 im replace but also same problem

[Jazz P Bass]

Check the power supply voltages.

[renz]

jazz power supply brand new.

[Jazz P Bass]

You still should check the 15 volt rails!

Something could be loading it down.

I do not have a schematic for the display part of the mixer.

Other than basic troubleshooting, I can afford no more advise.

[audiobrad]

Hi there all.

I would like you to cut the 5 volt wire coming from the power supplly to the main board.

Or even better pull out the digital efx boards and start the unit again!

[renz]

yes remove digital efx boards and install again it working display. and then 1 minutes is back again blinking light effect display.