Allen & Heath Mixwizard Channel 5 very low gain

[wilsonsk]

I tried "exercising" the insert jack in hopes that the contacts in the switching jack are corroded and some repeated insertion of a plug would get it connected again,  this did nothing to help, I still have a high pitched hissy noise on channel 5, not proesent on channel 6, with both turned up fully and no pad.  I didn't receive my deoxit yet, so I couldn't spray it yet, but in the past, a few insertions even dry should make a change.

I believe I'm back to ribbon cables?

EDIT -  I sprayed deoxit in the insert and exercised the insert jack again, no improvement to either XLR or HI-Z input. I then tried inputting in the insert jack part way to the ring connector with a mono 1/4" plug, and the it sounds the same on both 5 and 6.

More thoughts?

 

[wilsonsk]

Any ideas?

 

[wilsonsk]

Ok, I looked at the schematics, the signal path between the inputs and insert all go through the ribbon cable, so I'm going to clean them, any pointer on best practice here?

 

[wilsonsk]

I used deoxit D5 on the ribbon cables on the connector board and reassembled,  Channel 5 is normal, channel 6 was low. I had this happen before as well though,  and before, when 6 was low, increasing the gain control would make it "push through"  and start working.  This time I had both gain controls for 5 and 6 at 6:00 position and I ran the fader up and it "pushed through" and started working . I still haev some sort of issue with 6, and I'm not convinced yet that 5 is fixed, it has worked in the past since this started as well.

Thoughts?

 

[wilsonsk]

Well, I cleaned all of the ribbon cables for all of the channels. So far everything seems fine. I have to use the mixer Thursday, Friday and Saturday, so we will see  what happens, I won't be needing anywhere near all of the channels, but I will try 5 and 6 just to see if they are working.

 

[wilsonsk]

I have been sneaking up on it and trying 5 and 6, 6 is still doing the thing where if I run the fader or the gain up high enough, the volume to the headphones (not sure if to the mains as well, although I assume so). I'm satisfied that it isn't the ribbon cables. Hopefully someone will have a suggestion.

Did I post this in the wrong place? I haven't had a reply in some time.

 

[dax]

Spray Clean the back of the controls and switches on the intermittent channels- especially the assign switches

spray,actuate, repeat ...

Also be careful not to get de-oxit in the faders ... no good there.. kills the grease

 

[wilsonsk]

Ah, I'll give that a try,  thanks!