I have a Yamaha EMX5000-20 powered mixing board that my band has used for several years for live gigs and practice both. This past year i have taken it upon myself to learn how to cean and maintain it, because it really is a nice unit. Well, a few of the knobs were scratchy, as well as some faders. After a good cleaning, the faders were still the same. So i read up, and watched videos on how to rejuvenate the faders and thought i would give it a try as music is something that will never be over for me.
So i got copies of the service and user manuals, and disassembled it as the service manual instructed. I desoldered the faders (ch17/18, and ch19/20 from the circuit board and cleaned them up as the videos instructed. I was also under the impression that the Aux Send jacks were not operational. So i also desoldered those, and 2 from ch 17/18, and swapped them with each other, soldering them back into place. All seemed to be ok, until i got it put back together, and now my right side main is not working. I did all of the elimination steps, and it is definitely in the mixer somewhere. Both speakers and cables work when hooked up to a different mixer. Also, the right side LED meter does not show any movement while the left does.
I am certainly capable of repairing it, i just need a little guidance on where to start. I checked over the inside of the mixer really well, and all my solder points and things i changed, and i just dont see anything that looks out of place, broken, fried, etc. All fuses appear to be intact as well. Thanks so much in advance for any help that anyone can provide.
So i got copies of the service and user manuals, and disassembled it as the service manual instructed. I desoldered the faders (ch17/18, and ch19/20 from the circuit board and cleaned them up as the videos instructed. I was also under the impression that the Aux Send jacks were not operational. So i also desoldered those, and 2 from ch 17/18, and swapped them with each other, soldering them back into place. All seemed to be ok, until i got it put back together, and now my right side main is not working. I did all of the elimination steps, and it is definitely in the mixer somewhere. Both speakers and cables work when hooked up to a different mixer. Also, the right side LED meter does not show any movement while the left does.
I am certainly capable of repairing it, i just need a little guidance on where to start. I checked over the inside of the mixer really well, and all my solder points and things i changed, and i just dont see anything that looks out of place, broken, fried, etc. All fuses appear to be intact as well. Thanks so much in advance for any help that anyone can provide.
Panners all at noon.
Good call on the broken solder points. There are about 4 plugs to connect and disconnect In order to get down to the faders and pull them out. I was thinking on the 3rd or 4th time clipping and unclipping them, as they are kind of difficult "I hope I don't break one of these just messing with these plugs so many times."..lol I will give it a bit more close thorough inspection. I will also look up what a PCB connector and switch is.
By "Insert Jack", do u just mean the jacks in the back that i connect to my main speakers to? If so, yes there are 2 speakon and 2 1/4". One of the quarter inchers doesn't work. But we have always used the speakons with no problems up to this point.
Good call on the broken solder points. There are about 4 plugs to connect and disconnect In order to get down to the faders and pull them out. I was thinking on the 3rd or 4th time clipping and unclipping them, as they are kind of difficult "I hope I don't break one of these just messing with these plugs so many times."..lol I will give it a bit more close thorough inspection. I will also look up what a PCB connector and switch is.
By "Insert Jack", do u just mean the jacks in the back that i connect to my main speakers to? If so, yes there are 2 speakon and 2 1/4". One of the quarter inchers doesn't work. But we have always used the speakons with no problems up to this point.
no i had to go look at a manual, what i'm referring to are at the top right of the console and are labelled POWER AMP IN A/B.
you did say there's no signal appearing at the meter as well for the right side correct?
try the record out RCA's if you have signal there it means the fault is likely related to the EQ for that side.
( for sh@ts and giggles try some contact cleaner on the EQ on /off switch)
you did say there's no signal appearing at the meter as well for the right side correct?
try the record out RCA's if you have signal there it means the fault is likely related to the EQ for that side.
( for sh@ts and giggles try some contact cleaner on the EQ on /off switch)
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I mean those ribbon plug connectors.
Switch I mean those tiny switches on top of the faders for routing signals and the sliding ones on top on the right side.
Never worked ? Should be in parallel with the speakons and easy to repair unless one of the contacts is broken... but wait if there is a short on the jack the amp could be in protection mode.
Yes. Find out what's muting that amp !! lol
Suppose the faulty jack has a broken piece inside shorting the amp...
It's not uncommon poor cable jack tips breaking inside jacks.
I know You are pissed but I'm not responsible for that.
So we know the amps are probably working & the REC & VU doesn't work
Follow the service manual. Start tracing signals. Another amp & a wire with a capacitor & resistor in series makes wonders.
Check for signal after the strip, then at the summing amps bus ... EQ ... main amp.
Yes it is tedious but You will find the fault.
Oh no I'm not pissed at all. My apologies if I came across that way. I totally appreciate every nugget of advice.
I was trying to find where in the service manual I would find any Kind of troubleshooting like that. Would u know where in the manual to look for this type of tracing.? The inspections section.?
I was trying to find where in the service manual I would find any Kind of troubleshooting like that. Would u know where in the manual to look for this type of tracing.? The inspections section.?
Think I got it....lol
Ok...lol. Well, I think I found the problem. May have been slightly more obvious to the novices, but I appreciate the help all the same, as it got me really looking around for something a little harder to see. I wish I had a replacement jack to pop in and see if it all comes back to life, but I will get ahold of one, and go from there.
Just one more quick question for anyone still reading: In that second pic, the one of the whole circuit board, do i need to remove ALL of the phillips head screws around the edge in order to flip it over and resolder the jack.? Just wanted to make sure there isnt a less invasive way to do it before i get started. Again, thanks for all the help fellas.
Ok...lol. Well, I think I found the problem. May have been slightly more obvious to the novices, but I appreciate the help all the same, as it got me really looking around for something a little harder to see. I wish I had a replacement jack to pop in and see if it all comes back to life, but I will get ahold of one, and go from there.
Just one more quick question for anyone still reading: In that second pic, the one of the whole circuit board, do i need to remove ALL of the phillips head screws around the edge in order to flip it over and resolder the jack.? Just wanted to make sure there isnt a less invasive way to do it before i get started. Again, thanks for all the help fellas.
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I don't understand from the picture what You figured what was the cause.
The jack above has two wires and is correct. Pair 1- & 1+. The other under has 4 because it outputs both channels pairs 1 & 2. Look at the back of the unit. Jacks seem Ok. Just make sure the contacts don't touch each other. Even if they are loose and You re-solder them You still have the problem with the VU's. So the problem lies before the amps.
You follow the circuit in the schematic. First op-amp stage output, second one and so on..
All mixer strips go into a mixing BUS / mixing amp or several depending on features like PFL, Effects outs Groups etc. Then to EQ / effects section and then to the amps.
The connectors are also labelled, so that helps a lot.
Start by tracing the signal before the master pot. If both channels are there, mixer strips section is probably fine. Move on to the next stage.
Probably Yes.
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