Behringer Xenyx 2442fx

[Cr@sh]

Hello, I have a 16channel mixer/filter for our church that seems to have suffered some kind of input failure. 4 of the 16 channels 9/10-11/12-13/14-15/16 are stuck in "Clip" as if they are all four being clipped by an input device. Currently I have it taken apart to look at any obvious failures such as burned parts and I have checked most of the OP's (V4580M) and as far as I can tell there fine, but there is like fifty of them on the board and I haven't checked them all.


When I first turn it on it's fine but after about five minutes all four channels go into clipping. Can anyone help point me in the right direction on where to start looking for problems? Thanks

[Cr@sh]

Update: I just now noticed that when I move the volume for each of the four channels up the clip light grows dim until I reach the top then it goes to full red again. Also when I press the "Solo" button the clip light goes out completely and stays out.

[fredy2]

Here is a schematic... this is a 1204, yours just has more channels... duplicates:

BEHRINGER XENYX 1204FX Service Manual free download, schematics, eeprom, repair info for electronics

The circuits of interest are on sht 3. The "volume" you refere to is the "fader". I would suspect that the amp following the fader is loading down the clip detector is why the dimming occurs. This should be easy to find the problem. I would suspect power supply to the op amps and the electrolytic coupling caps. These units are ESPECIALLY vulnerable to spilled liquids and I have seen power rails etched and burned through.
At the site, find the link "get manual" and click on it to download. The site is in Hungary and is the only real source of Behringer dwgs I have found.

[Cr@sh]

That makes sense! The small mixer we have in its place is over heating, my first thought was amp is somehow back feeding into the mixer. Thanks for your help fredy, this should get me in the right direction and fixed!

[fredy2]

Remember this CARDINAL RULE. ALWAYS power ALL interconnected equipment from the same receptacle or power conditioner, even if it means running an extension cord from the amps back to the mixer. Ground bounce in building wiring fries many a piece of audio equipment.

[Cr@sh]

Originally Posted by fredy2

Remember this CARDINAL RULE. ALWAYS power ALL interconnected equipment from the same receptacle or power conditioner, even if it means running an extension cord from the amps back to the mixer. Ground bounce in building wiring fries many a piece of audio equipment.

Thanks I'll check that out, i'm sure not all of amps, computer and other items are powered from the same place. I'll also check all the outputs (Which would be inputs to the amps) and see if there is voltage or current present (coming from the amps) as there shouldn't be.

[mnemneth]

From Post #3, I searched further and it seems the 2442FX is also on that website;

Service manual, eprom result list | ElektroTanya | Service manuals and repair tips for electronics experts

Full circuit diagrams.

Excellent website, well worth bookmarking.

Sandy

[Cr@sh]

Thanks Sandy

[fredy2]

[QUOTE=mnemneth;2615182]From Post #3, I searched further and it seems the 2442FX is also on that website;

Service manual, eprom result list | ElektroTanya | Service manuals and repair tips for electronics experts

Full circuit diagrams.

Excellent website, well worth bookmarking. end quote


Yes Sandy, the Xenyx version MIGHT be slightly different than the raw 2442FX version but it is worth comparing. I found this site over a year ago and I periodically send them a $10 contribution which is about 2000 of their currency in Hungary... I have downloaded hundreds of schematics from them.