1994 eurpoa with noise

[hgregs]

hi all... i've had a noise problem with my 1994 europe for a while. i've sent the electronic harness into alembic, i've swapped out the main chip, i'm about to change some op amps that were recently sent to me... but wondering if anyone has experienced anything like this?

https://photos.app.goo.gl/oi1cxU3vSSWR7KCW8


that's a guitar tech diagnosing


i know it sounds a little like cell phone noise.

[edwin]

Sounds to me like a bad power connection in there somewhere or else a bad cap. Does the signal go in and out with the noise, or is the signal stable?

[mario_farufyno]

That kind of noise is tottaly new to me, never experienced anything like it...

[jazzyvee]

A few years back I had what seems on the surface to be same problem as you are having, at least the noise sounds similar though yours is more continuous. I did post something about it back then and here is what I wrote.

"My Europa had jack problems it kept crackling and cutting out I changed it for a new one that was kindly sent to me free of charge by a forum member in the USA. Subsequently to that i've found that the same problem exists if I use leads with moulded plastic jacks since the plastic extends marginally further down the shaft of the jack making it slightly shorter than a metal housed jack plug and as a result doesn't fit far enough into the socket to snap into the clip inside."

Let's hope the issue is as simple as mine was to solve. After that experience with both my Europa and my Orion guitar, I replaced all the jacks on my leads plastic to neutrix metal ones and don't have the problem. The dodgy jack probably exacerbated the problem.

[hgregs]

edwin - the signal i get (from playing) is stable, regardless of the level of noise.
when you say cap, do you mean to the battery? that black 9v cap was recently replaced.
 
jazzyvee - i'll see about making a change to the jack (which has been replaced recently to try to solve this).

[keith_h]

Edwin was using the abbreviation for a capacitor. I agree it sounds like that, maybe a bad solder joint or component lead, a broken wire or other bad connection. 

You said you've sent all of the electronics to Alembic for testing? If there was something wrong on the boards I suspect they would have found the problem.

Has your tech put a scope on the electronics to see if he can chase down the problem? With a scope, no guitar chord and power switch of the jack shorted does the bass still make the popping noise? If it doesn't then I would suspect the jack or its wiring. If it does, have you disconnected the pickups one at a time to see if it is related to one circuit or the other. As I recall they each have their own preamp. How about disconnecting both pickups? The tech should be able to follow the circuit board traces to make a schematic to work from.

[hgregs]

new chip and capacitors... so far so good.

[mario_farufyno]

Great to know the problem was solved

[jazzyvee]

Great.

[CLAIR]

Decent, need to accomplish something like this with mine.