Mackie 1604 vlzpro intermittent volume drop

[shortcircuit]

complaint volume drops 50% or better,not completely out , happens regardless what input or channel is in use, bumping the fader up will bring it back . I went over to hear it for myself and of course it wouldn't fail . I told them to keep notes to see if it happened roughly around the same time ,thinking something is getting hot and failing. Report back was intermittent ,sometimes happens at start up , 20mins 30mins etc. I've search through MEF archives but didn't see anything with this problem, any suggestions ??

[eschertron]

That link is dead.
Without knowing anything about the mixer, has the client tried a lube/cleaner/restorative on the fader track?

[shortcircuit]

it's not just one track , it does it regardless of input on all tracks ,to answer the question no I'm sure they haven't messed with anything, other than running the Mackie powered speakers with another mixer to isolate down to the 1604. Sorry about the dead link, I'm working on it.https://supportloudtech.netx.net/lou...category/11527
sorry I can't get my downloaded pdf to load

[eschertron]

The Loud Tech portal is pretty handy, good source of info.

To be clear, when it happens it happens on all channels simultaneously? Or individual channels randomly?
Bumping up the fader will allow the user to compensate for the volume loss, or "bumping a fader" restores the original volume?

[shortcircuit]

The Loud Tech portal is pretty handy, good source of info.

To be clear, when it happens it happens on all channels simultaneously? Or individual channels randomly?
Bumping up the fader will allow the user to compensate for the volume loss, or "bumping a fader" restores the original volume?

I can't be sure of all channels simultaneously , although they did say it happens when his grand daughter is singing, so I'm thinking she's singing along with a CD, phono etc. and it all drops. Bumping fader up kicks in volume ,then you can return to original volume from my understanding. I've yet to see the failure first hand , I'm heading back there today , hopefully I'll be able to be more precise after that. I can say I know the history on this , it hasn't been moved over a dozen times and it's in a room most would consider a "clean room"

[shortcircuit]

If I didn't know this guy I'd say he's hearing things , listened to some great music for a couple of hours , never heard a volume drop . I brought it home just to please them , I'll clean the jacks , give it a once over , recommendations on cleaning fader tracks ??

[nevetslab]

If I didn't know this guy I'd say he's hearing things , listened to some great music for a couple of hours , never heard a volume drop . I brought it home just to please them , I'll clean the jacks , give it a once over , recommendations on cleaning fader tracks ??

The Mackie 1604 VLZ3, and all in that series.....the multiple PCB's are all interconnected with IDC-based ribbon cables. For some reason, these extremely popular mixers in the Film / Video studio industry suffer from random signal dropouts, and, besides the rotary pots, pushbutton switches and slide faders, all of which also get gritty from use, the ribbons become intermittent. The standard solution we used at Westlake Recording Studios' repair shop on Santa Monica Blvd, West LA, was to replace the entire set of ribbons. Now, that's a chunk of change. I've done it as well, by chopping off the IDC ends, and pressing in fresh IDC connectors, as there IS enough cable length to do it at least once, as long as you're careful.

I never did buy into the procedure of spraying in contact cleaner thru the pot shaft openings, as it destroys the viscosity feel from the greased shaft/bushings. The pots that really suffer are the Gain Trims.....that last 15 deg of rotation where you get to max gain is ALWAYS nasty as they age. I've pulled the pots out, pulled them apart, cleaned / lubed them, put back together and re-installed them with far better luck than spraying down thru the shafts. The switches.....just as with the pots....exercise the dickens out of them, and replace the ones that don't come back to being stable and quiet. The slide pots....I've cleaned the tracks on those after pulling them and lubricating the resistive elements. Or, just replace them.

They are tedious to disembowel. Also, the power supply on those run VERY HOT...something they've never cured, nor did I get any proper solution to improving upon. At Westlake, we used to service these on a regular basis....maybe 10 per month.

[The Dude]

^^^^^^ What he said about ribbon cables. I worked for a Mackie warranty station years ago and we replaced tons of ribbon cables. And, they can be horribly intermittent. Last I knew, they were on revision 'G' for ribbon cables in the VLZ series. Seven revisions to figure out a f'n ribbon cable. It's a bit ridiculous. I'd pop it open and see what the revision number on the ribbons is.

[TimmyP1955]

We've fixed many a Mackie by just opening them up and "exercising" the internal connections.

[g1]

Which output? Any or all? If it's just one side (for example) I'd normally think fader or insert jack for that output.

[shortcircuit]

Which output? Any or all? If it's just one side (for example) I'd normally think fader or insert jack for that output.

Client says it happens regardless what channel your using, as I stated I have yet to hear it happen . User interface ?? I did notice they were using a lot of adapters rca to 1/4 etc., numerous places for gremlins. But it is 18yrs old a good cleaning shouldn't hurt anything. I'm keeping all suggestions offered in mind along the way. Just had a Carvin XB700 with a ribbon connector issue, that sounds very plausible.

[eschertron]

The switches.....just as with the pots....exercise the dickens out of them

That's what I've discovered from my (limited) experience with boards of this price point. I've been through a couple Behringer boards, and the 'self-lubricating' sealed switches NEED to be exercised routinely or they get dodgy. Bus selectors, mute switches,.. I have brought a channel back to life with dozens (hundreds?) of button presses. No guarantee that it'll stay that way for any length of time. Big hassle.

[g1]

Client says it happens regardless what channel your using, as I stated I have yet to hear it happen .

The channels he is talking about are inputs. That's why I'm asking about which output he is listening to. Maybe you are listening to a different output buss and that's why you don't hear it. If nothing else, it should help narrow down the troubleshooting if you find out which output he uses, could be left, right, mono, monitor buss, whatever. But when he says 'channel' I can almost guarantee he means input channel.

[shortcircuit]

I'm sorry , yes he's talking input channels . Outputs : first they said they were using the L & R and the R sounded weak , so he started using the L & mono , then he started getting this volume drop off . I have it here now, I did a quick hook up using L & R outputs , both sounded normal/equal to me , output meter led's are even ,no weak channel , so far no drop .

[eschertron]

I'm sorry , yes he's talking input channels . Outputs : first they said they were using the L & R and the R sounded weak , so he started using the L & mono , then he started getting this volume drop off . I have it here now, I did a quick hook up using L & R outputs , both sounded normal/equal to me , output meter led's are even ,no weak channel , so far no drop .

Bad/oxidized jumpers between board and PA? Be sure to clean up all the interconnects and jacks external to what they customer brought you if that could be an issue.