Connect lexicon mx200 to a mackie 24 channel mixer board

sounds like it could be dust or moisture ...Try cleaning the board and knobs and faders. this may help it may make it worse. Also while at it...check all connections...especially from board to amps. or to outboard gear. Could be a bad chord

you have to set a master and slave(s) devices, and ensure that all the timings (16/24 bit, the 44.1/44/96k) are consistent in all devices

Cleaning may be an issue, maybe try putting something under it to air can get to the bottom. I've had to do that with my mixer.

If unt was dropped, look for broken PC board in the vicinity of the rotary encoder. Also look at solder connections to make sure they are sound. A little contact cleaner applied to encoder through an opening so the spray gets inside will help clean contacts. If the knob itself is hard to turn, the shaft is likely bent, and there may be damage to the encoder itself.

hello I have the same problem, I'm told that updating the firmware of the Lexicon MX200 is solved but it turns out that my pc does not recognize the device via USB to update, any solution? thank you very much

one CAN join two soundboards BUT at the expense of a higher noise level. You would come out of mains of the slave one and into inputs of the second (master) board. There are many configurations one could do I would suggest bringing these inouts from the slave board into the "AUX RETURNS" jacks.
Use TRS cables (balanced) for the interconnects.

Decide if you want to use the AUX's or the SUB's for your monitors. (usually use the AUX).

Connect TRS cables from the appropriate AUX sends to thee amplifiers you use for your monitors or your powered monitors whichever you have.

Adjust the level using the AUX level controls for each channel to set your minitor mix.

Normally use the PreFader AUX's so monitor levels are set independent of the slide fader positions.

Here is a big hint for you: Search YouTube.com for "Soundboard" or "Soundboard setup". There are good videos there that might be different than your particular board, but there is enough commonality that you will soon be an expert!

I suspect one of the upfront IC amps has been damaged. This can happen if people power the mixer from a receptacle that is different from where other connected equipment is powered such as amp. For example, mixer is at one end of the hall and other inouts such as an output of a guitar amp is plugged in. If a ground fault or spike occurs, teh ground bounce can exceed the common mode voltage of the input amps.

In your case, the inpout amps are discrete transistor types.

A voltage surge into the inputs of your unit would LIKELY pop two bypass caps that are 330pf. For channel 2 these are C205 and C206. Check those for shorts.

VERIFY audio is available at the "send" (tip) of the channel insert connector... this verifies the preamp stage. You can PROBABLY plug a set of headphones in to check this... ONLY one side will have sound of course. Verify this is a good test by checking a working channel. The level will be quite low and we are looking for just some signal.

IF you do have signal on the channel insert send which is the "tip" of the channel insert with the trim turned up, let me know and I will check the schematic for the next thing to check farther down the line.

Refer to your EV user manual, page 23, part 2.

You run the outputs of the Mackie into the stereo "returns" on the EV.

Use TRS interconnect cables as these are balanced lines.

If all other functions work for those channels, the most likely problem is the fader itself. These can fail and operate more like switches rather than faders. Without witnessing the behavior, I can not state that for sure. While these mixers are not the hardest to work on, they are time consuming. The faders can be purchased from Mackie directly. If you need to have this repaired, any shop that repairs audio gear should be able to erpair this for you. Where are you located?

Dan