Charvel Model 4m electronics issue

[RampantLion]

I purchased a 1988 Model 4M today and it has an electronics issue. I am not a tech, so I don't have any tools to test the parts. I was hoping to get some advice as far as what it could be. Basically, I can get sound, but it cuts in and out, especially if I touch any of the knobs or switches. All of the solder points look good and I replaced the battery in the JE-1200 pre-amp. Would I be best to take it to a guitar tech or should I try to replace the pre-amp? I appreciate any and all help.

[Matt_B]

If you don't have the proper equipment to test things out just take it to a tech and get 'era done right the first time.

[Iceberg794]

Clean the electronics with deoxit.

[JACKSONFREAK]

Try cleaning the electronics first like mentioned above. If that doesn't work take it to a tech. it could be simple or difficult.
Gil

[RampantLion]

As always, I want to thank you guys. I always appreciate the tips, even if I come here with some n00b questions. It was indeed oxidation in the knobs. A few sprays of Deoxit and it's a gem again! This guitar is absolutely amazing! I now own 12 Charvel models of all varying years and this is right there towards the top. I just can't get over how beautiful the neck is and how great the tones are!

[RampantLion]

Here she is after a good set-up!

[BayRocker]

Very nice...I'd like to get my hands on a maple neck M4 someday. I played my M4 for the first time in a while earlier this afternoon...still my favorite player after all these years.

Glad to hear the spray sorted out your issue. I get the same thing in my M4 every few years...quick spray and good as new. Only thing I've had to change on that git in 27 years is one of the mini-switches and that wasn't even due to failure. Some d-bag banged into it while it was in the stand snapping the lever off the switch.

[Carbuff]

Thats a pretty color combo. I like it.

[RampantLion]

The seller obviously never played it or took it out much. There is little to no fret wear and it was just a matter of spraying contact cleaner into the knobs and setting the action.

One issue I do have and I've actually never heard it this bad on a guitar, is a horrible hum/noise when I use the bridge humbucker. I don't get the noise in either single coil, but if I turn up the knobs and use the humbucker, it's excruciating. I use a Rocktron Hush pedal which does quiet it up, but then you lose a lot of the harmonics, etc. Any ideas as to what it could be?

[RampantLion]

I took it to a tech today and he said he had never come across a pre-amp like that, but it appears one of the caps is bad. He also said there appears to be cheap knobs and an issue with how the pot attaches to the preamp. But wouldn't that effect all of the pickups and not just the humbucker?

[RampantLion]

I took the guitar to another tech and he tested everything. Everything checked out fine with the preamp and 2 single coils, but he said there was a bit of a grounding issue with the humbucker. Has anyone had an issue like this with a Jackson pickup and a JE-1200 preamp? Before I purchase another Jackson pickup, I'd like to get some feedback. Since I want to keep it as original as possible, I definitely want to replace it with another Jackson pickup, but I want to match it with the best humbucker as I can for the preamp.