Background:
I have been reporting off and on here this problem where my MnM doesn’t boot the OS upon power up and just sits there lit up like a christmas tree. Here is one of the (many) thread about this:
I’ve been having this problem for years and actually my machine has been into Elektron repair three times I think. The issue seems to be bad connections with the connectors between the various boards. The problem would always be resolved but then would come back after a couple months. Well I got sick of sending my MnM in every time so I started opening it up myself and reseating the connections as Elektron actually just recommended that I do. This has always solved the problem for a little bit… but it would inevietbally come back. I have done this four times now.
Well this time when I opened up my MnM to reseat the connectors I actually used Deoxit to wipe the pins and I sprayed some into the female connector ends too. I was very careful not to have it get everywhere and made sure the pins were properly wiped and the connections were seated as securely as they could be before putting it back together. I power up my machine and it looks like it works!
Current Issue:
BUT… then I actually hook the audio up to my system and play some patterns… and there is some messed up behavior from the audio outs. Here’s what I observed:
- The master volume knob doesn’t do anything. MnM pumps out full volume both to headphone outs and output A and B even with the volume knob turned all the way down… and turning the knob makes no difference in level at all.
- Audio only appears on the right (B) channel. Both in headphones and master outs.
Everything else seems to working just fine and my headphones, mixer, and all cables are working fine with other devices.
I am worried I messed something up with the Deoxit… or could this be a connector that was plugged in reverse or something? Before I open up my MnM again and go messing with the connectors and before I contact Elektron support I thought I would check here to get some wisdom from the nauts.
What variety of Deoxit did you use? I only ask because I’ve been told that many kinds are too aggressively “solvent” for using on old pots. I know you said you were careful and I’ll admit I’m not very familiar with the internal layout of MnM but the problem you describe sounds like a potentiometer failure for the master volume. I’m wondering if maybe some contact cleaner got between the wiper and the element of the pot.
only thing I can think is maybe a couple of the pins might be shorting to each other and maybe one of those pins has to do with the master volume. I would try to clean out the female end of the connector as much as possible and make sure it is dry inside.
You’re fine with the deoxit on the pins and the female connectors, but if it is the more aggressive type of deoxit with a higher concentration of contact cleaner then you want to keep it away from the pots/encoders.
That said, it sounds (to me) like there could be an issue manifesting with your volume pot itself. Deoxit of any type (except the straight lubricants like fader grease/lube) the solvent part evaporates super quickly so there shouldn’t be any issue with liquids as a result of use.
It sounds like the short is possibly inside the pot itself, since the pot is just a variable resistor, one end of it makes no contact, one end makes full contact. Sounds like it’s pegged at full contact and turning it doesn’t cause the wiper to hit the resistive carbon strip like it’s supposed to.
If you have a multimeter, test resistance on the pot with the shaft in both directions and see if it has the same reading on both ends because that would support this theory. As far as only the right channel, if it’s using a dual gang potentiometer it’s possible for half to fail completely, and the other half to be malfunctioning as described but you’ll have to do a little poking around to see if any of that is heading in the correct direction as I’m sure that there are potentially other reasons you may be limited to the B channel.
Thanks for the replies everyone I really appreciate it.
Yeah it does seem like a volume pot failure, that would be the most logical. Thing is, I didn’t spray any Deoxit anywhere near any of the knobs. I removed the top board and set it aside and just wiped the connector pins on the underside of the board with a q-tip soaked in Deoxit.
@Sip I used Deoxit D5. (Attached pic) I thought this was the one to use for connections. I guess I didn’t really look into all the different kinds and what their best use cases are. I should have done much more looking up before using it for sure.
@bwo Could the Deoxit cause the pins to short if sprayed in the female connectors? I suspect that I might have connected something in reverse with the pins flipped around when I reattached the connectors.
@shigginpit Thanks for the detailed response. I’m going to open her back up now and check out the connectors again and will look at the volume pot too… but I don’t have a multimeter so not sure what good a visual inspection will really do. I’ll see…
I think D5 is contact cleaner without lubricant, for the connectors it should be ok but I wouldn’t use it on pots (which you didn’t).
While it does sounds like pot failure, without obvious catalyst I wouldn’t call it a natural conclusion, really needs more testing. It could be something else, an opamp, who knows.
Let us know if there’s any other evidence or symptoms after you take another peek inside.
Cause: The 6 pin connector that links the upper control board to the lower IO board was connected in reverse to what it needed to be.
Here is what I discovered with some labeled pictures. Reported here for posterity so as to help other people if they run into this issue when reseating the internal connections.
Process:
So, I opened her back up and checked out the volume pot first and saw all the leads and pins to the 6 pin connector were clean and no signs of any shorts or weirdness (I didn’t use Deoxit on the pot anyway).
I reseated all the other 2 pin connectors the same way they were with the little clips the “right way” around and they all looked fine. By “right way” I mean the clip part on the male end nests against the side of the female end with the “ramp” shape.
Then I check out the other end of the 6 pin connector that goes in the underside of the upper control board… and I noticed that the clip part of this connector is bent some way apart from the body of the connector which isn’t the case with the others. (Although many of the others are indeed pretty loose feeling) Suspect!
So, I flip around the connector and connect it in “reverse.” This means the ramp on the female side is connected facing the other way from the clip on the male side. (See color coded pic below)
This was the only thing I changed, so I connected my MnM and powered it back up and discovered that the problem is solved, so this must have been the cause.
When I reseated the connectors the first time I connected it the “correct way” which the clip was designed for and strangely this turns out to be not way is need for the MnM… or at least my machine in particular. This seems really weird to me. It seems that every other time I have reseated these connections I wasn’t really paying attention to which way around the clips go and just luckily got it right.
I would be curious to see if anyone else can open their MnM and confirm which way this 6pin clip is seated on theirs.
TLDR: When reseating the 6 pin connector the lower IO board should be clipped in the correct way but the upper board connector should be flipped around and connected opposite!
Thank you very much for describing the problem and the solution!
It seems that in your case specifically, the incorrect positioning of the connector on the front panel PCB was due to an oversight during assembly at the Elektron’s factory.
By the way, it should be noted that not all MD / MNM have connectors on the front panel board. More often than not, I have seen units where the wires were soldered directly to the front panel PCB, and connectors were only on the mating part.
