Encoder Knob NOT WORKING!

[mr_debauch]

Hey guys, Yep I'm new here, yep I sorted through pages and pages of search results on the forums before posting, and nope... I cant seem to find anyone with my particular issue.

I have an ultralite, and one day during normal typical use the main volume knob all of a sudden sudden stopped controlling the volume. My interface is stuck permanently at 0db (I have never once turned it that loud) it just went to that level and is stuck there.

Here is what I know:

-It is not physically broken, the unit is in brand new shape. When I power the unit on, and I turn the knob for the first time it will display the db level (0db) however it will not change it. I will add that any time I push the knob in it shows the level as well so the clicker is working fine all the time. Any time afterwards though the knob does nothing until I turn it off and then back on again.

-Through playing around, I discovered how to get into the untralite's debug mode. For those that dont know already, while the unit is turned on you hold all four of the buttons on the right (not the input trims just the four knobs at the right) and let go before it powers off... then go into the menu and scroll through the options to see a new menu called DEBUG. It may take an attempt or two for it to work but it works. That mode has a knob and button diagnostic/checking tool built in! all knobs and buttons are shown as active... except for the main volume knob. I can scroll through the hex values with every other knob on the thing. None the less, discovering this debug mode was like finding out about the konami contra code for me... I was excited!

-I know it can not be a physical issue. I ruled that out above... so I figured it is something to do with a glitch in the firmware. Problem is the unit is at the latest version since I owned it. I downloaded the updater anyways though.... but both my computers running vista 32bit dont seem to be able to run the vista 32 bit program for the updating process. I can launch the app fine, but if I boot the ultralite into update mode and try and launch the app.... the app crashes right away and cant even launch. I tried launching the app before booting the motu, that does nothing. I am planning to try and dig out my old XP athalon machine however I am not sure it has a firewire port... I cant remember. So that is the one thing I thought of that I did not try. Sorry for posting before trying that.

-using the reset feature in the motu menu does not do anything either.


Now some theories I have, or idea I think might help... flashing the OS/firmware. I think that may help since the problem is not a physically broken knob?? is that possible? Or is there a physical reset switch or a battery or something internally that can be reset? I have never opened one of these before.

I called motu, the tech guy seems like he knows less about the unit then I do... he didn't even seem to know about the debug menu that I discovered. In fact I will go to the extent of saying that he seemed more like a salesman because any thing I tried asking his opinion on resulted in him saying "no regardless of what the real issue is, I guarantee you that it is not possible for you to fix it yourself and you must send it to us (which will cost 100 US dollars)"... That is ridiculous!


Anyways /rant

can you guys offer advice?

[1nput0utput]

It is possible for the button function to work while the knob function does not. The knob is malfunctioning, and the interface must be repaired.

[HCMarkus]

You could try a little contact cleaner in the encoder... Caig Labs DeOxit or Pro Gold is wonderful stuff and should be in every studio. Saves the day on all electrical contacts, and work on scratchy pots really well. For moving faders and pots that you want to feel some resistance in, try Caig's MCL.

I love this stuff, don't work for Caig, and never inhaled.

Another possibility is a busted lead or solder joint inside your interface. Save $100 and find it yourself, if you dare!

[1nput0utput]

The knobs on the UltraLite are digital encoders, not analog variable resistors like you would find on an analog console or mic pre-amp. I don't think a de-oxidizing solution will help. In fact, it might damage the encoder further. I'm not totally sure, so proceed at your own risk.

[HCMarkus]

An encoder is, I believe, a series of contacts, as opposed to the continuous swipe offered by a potentiometer. I have successfully improved (and never harmed) the performance of several encoders with Pro Gold over the years.

From Wiki:

An incremental rotary encoder, also known as a quadrature encoder or a relative rotary encoder, has two outputs called quadrature outputs. They can be either mechanical or optical. In the optical type there are two gray coded tracks, while the mechanical type has two contacts that are actuated by cams on the rotating shaft. The mechanical type requires debouncing and is typically used as digital potentiometers on equipment including consumer devices. Most modern home and car stereos use mechanical rotary encoders for volume. Due to the fact the mechanical switches require debouncing, the mechanical type are limited in the rotational speeds they can handle. The incremental rotary encoder is the most widely used of all rotary encoders due to its low cost: only two sensors are required.