Rane Mp2016s Rotary Mixer XLR Signal Problem/ Technical Help

[matija]

Hi everybody,

my name is Matija and I am owning a pretty cool Rane MP and XP 2016s Rotary Mixer. I bought it a couple of years ago used, but the Preowner didnt mention there was an Problem with the left XLR Signal. I just keeped the Mixer because the Price was very cheap and i thought to fix it by my self. I thought also, to find the Problem, isnt that difficult.

Why did I thought it isnt difficult? If I power up in the Mixer, the left XLR Signal is dead. But after a while,( maybe because the Parts are heating up a bit? ) I can get the Signal back by hitting the Enclosure at the downside of the Mixer. I need a few trys, maybe some Minutes or just Seconds to get a stable but probably unequal (Volume) Signal. Also, i can manipulate the Signal by Moving the Female Connector around from the Speaker while pluged. Because of this Sympthoms, and because I can get the Signal back by hitting the Enclosure, I thought its not difficult to find the Problem. It could be just a loose Connection or a Ground Problem somewhere? If the Signal is down, its also down on the RCA (where my dB Meter is connected) on the House Outputs. So i leave the Mixer always connected to Power to avoid losing the Signal. But sometimes i just lose the Signal again, even if its pluged to Power, but this is a pretty rare Case. Also, sometimes its buzzing a bit (like in the provided Video) and its easier to get the Signal back if the low Frequencies are loud (Bass).

So, what have i tried so far?
- I switched everything from left to right (like the Speakers and the Cables)
- I opend the Mixer (someone opend the Mixer already cause the screws are a bit used), soldered the XLR connecter from the circuit Board away (measured the connectors)
- Removed a bit of the Painting from the Screw on the Jack J26 which is Pin 4, connected to Ground.

Schematics MP 2016s
Product documentations
Video
I plugged the Mixer back to Power and it was working flawles at the Beginning, but i was suspicious and i moved the XLR cable around and the Signal went dead again after a while. So, again, hitting the Enclosure and Moving the XLR Connector around to get the Signal back. If its back online, dont touch anything anymore ^^.
Im not good into reading schematics but since the RCA and the XLR are going offline simultanious, the Problem should be somewhere else.


So hopefully, you guys can give me an Advice or some Inspiration where to search for the Problem.

 

[matija]

the 34 pin ribbon cable was the problem

 

[squarewavebeach]

Hi Matija,

I have the same problem.
The signal of the Left XLR Output goes dead after a while.
After knocking gently on the backside around the area of Booth, House and the Effect Loop section the signal comes back.

Tried it with unplugging the external MP + XP connection ribbon cable, and changing the left and right XLR output cables - problem still remains.

Any ideas what I should do next / where to look on the PCB? I sent the MP unit to a service center twice and they couldn't find the problem.

Thanks a lot in advance!

 

[squarewavebeach]

Oh I thought you meant the external ribbon cable.
After counting the pins I realized its the internal ribbon calbe that has 34 pins.

Gonna get me a new one and test it.

 

[Mask]

I have exactly the same problem. It started when I moved my mixer around and I lost the signal in left channel. After finding this thread, I opened top panel case to reveal top connection of the 34pin ribbon cable and I carefully started to touch the connector while the mixer was plugged and I got the signal back. In some position the signal from L&R are equal, but as soon as I move my hand from it the left channel is lower in volume. Can you please share how did you solve the problem? Have you bought a new 34pin cable or have you just reset it at the connector? If yes, what is the part number of the cable or where have you bought it?

 

[AnalogSteph]

You may want to post a picture of the connector so others can get an idea of why it may be problematic and possibly give tips regarding how to undo it. After a few decades, a bit of contact cleaner may be all that's needed to restore proper operation.

 

[Mask]

The wide 34pin ribbon cable from the top ("J303"). If I want to get to the other side of it I need to dismantle the whole casing with all the screws for different I/O connectors at the back. Before I get to that I want to be on the safe side and have the replacement cable in case its bad. I did unplugged it and plug it back in case it got loose, but no difference, only if I push on the cable from above in some position I get the equal output.