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Active EMG output issues and troubleshooting

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Hey everyone. I'm new here to the forum,  or any forum for that matter. I'll start with some background. I have OWNED and played guitar for about 15 years now. However, I emphasized "OWNED" because realistically I've only gotten serious about it 3 or 4 years ago. 

I've always done my best to troubleshoot and fix anything in house, including instruments. On that note, regardless of putting a number on my experience, I am entirely self taught. In turn I strongly believe my knowledge of how everything works or even my knowledge in music theory is limited to say the least, but I do certainly have a basic understanding of most things and will never claim to know more than the next guy.

With that being said I'll get started with the issue at hand. About 2yrs ago I purchased an ESP Ltd ec-401 with emg active pickups. It is the first and only instrument ibe had any first hand experience with that has active pickups. And I have no issues with the guitar until now so I really havnt learned any more than the basics about active pickups.

I keep my big rig in the garage for multiple, and likely obvious reasons. Well it's been pretty cold here recently and I heat the garage with a large salamander, and I keep it a minimum of 60 degrees all the time. 

Well the other day, I had just finished stringing the beast and putting a new battery in. I set it on its stand in the garage and went inside for a moment. When I came back out the wife was smoking and she must have been cold cause she had the heater cranked haha. Well, unfortunately she took no notice of the guitar sitting 5ft in front of the flame that wasnt on when i put it there. It couldn't have been there under direct heat more than 90 seconds, just long enough to soften and bubble a small spot of lacquer, upsetting but whatever I can move on. 

Then, to my surprise, I plugged in and when to picking and got nothing! Upon playing around with tone, volume on amp and guitar as well as the selector and amp channels I discovered I had the least sound playing on the clean channel if any sound. Yet as I add crunch or go to the overdrive channels it's actually seemingly gain a minute amount of volume. Immediately I also noticed the every channel sounds perfectly clear no matter hj owuch gain or overdrive I throw at it, it had no effect. Also, it would appear that the neck pickup puts out the least, honestly more.like.no output.

So, the heater was actually blowing on the back of the guitar just below the neck next to the selector cavity.

I've got everything opened up and nothing appears melted inside in any way or show any sign of an issue. 

Any ideas what could be wrong and/or how I can troubleshoot and diagnose using a multimeter, or any other method? I've t ess sted all the other gear, the amp and cables with my les paul and everything is good there.

Any help or advise would be greatly appreciated! Thanks for your time guys. I love.all my.axes but none hit just right for down and dirty metal like these EMG's. Cznt wait to have it working again so my ADD self can continue to bounce around sounds amd genres! 

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Well, I've owned a guitar or a dozen since the late 70's and I still haven't gotten serious about it. And I've never had any active pickups so take the following with some salt.

I tried to read and re-read your post but I couldn't find whether you put in a new battery also after the incident. I mean, the battery may have died of that sudden heat wave. I'd start with that since it takes the least effort.

Other than that, I've taken paint off with a heat gun while renovating my house. Apart from a couple of burn marks on the very surface no damage was done to the material underneath the paint. Of course your salamander is a lot bigger but 5 feet is also a lot farther away than 5/8". As you said, no obvious damage could be found. In my thinking the plastics should have melted before any solder joints but without taking it all apart a closer visual inspection can't be done. A multimeter might be a good idea. I'm not too familiar with those, but the beep function for checking continuity might be of use, telling if a hot wire gets prematurely grounded.

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4 hours ago, norm barrows said:

heat hot enough to melt lacquer can fry chips. why do you think they put those massive heat sinks on PC processors?     take it off, the chip shoots to 250 degrees F in about 20 seconds and fries.

Agreed, however the wood itself acts as both an insulator and a cooler block. And the cavity beneath also has an insulating space of air between the heater and the electronics. Wood and air don't conduct heat well, so it's hard to believe that the inside of the control cavity could have gotten hot enough to damage the electronics.

BTW that video is OLD! Even AMD has had a similar overheating protection for the last decade or more so fear not, you fellow computer users, your CPU won't fry if the cooler block gets loose.

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OK so lets actually troubleshoot.  I assume you have a multimeter.  so... take the black lead and clip it to the black lead on the neck pickup.  take the red lead and clip it to white.  set your multimeter to ohms/resistance.  you should read somewhere in the 8-10k range (not sure on these pickups but should be in there somewhere. 

assuming that goes well... clip black to ground lug of output jack.  red lead to the red wire for neck pickup.  change multimeter to voltage reading.  are you reading 8-9.5v? 

then repeat for bridge.  this will tell us if we have working pickups and if they are getting juice from the battery.  if you aren't sure of how to get votage/resistance on your multimeter post a pic or tell the brand/model.


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