Electronics repair

brian · Post by **brian** » Tue Apr 06, 2004 9:19 pm

Does anyone know of a repair person who is good at electronics ? I have a problem with one of my guitars and took it to a local repair place. They worked on it for a couple of hours and had an electronics person check the board, but were unable to fix it. They suggested it may be a pickup problem, but the pickup works for some settings. There is one positon on a rotary switch which does not work. We thought it might be the switch and replaced that , but the problem still exists.

admin · Post by **admin** » Wed Apr 07, 2004 12:18 am

Brian: Is this a Rickenbacker? If not, why not post it under the Toneman section and see what Don has to say. A more detailed description of the make of guitar and its pickup and electonics would be helpful.

brian · Post by **brian** » Wed Apr 07, 2004 4:16 am

Yes, Peter it is a Rickenbacker. It is a 381JK. Sorry for the confusing post, I'll try to be more clear. The problem is that when in the Rotary select switch position 1 (rhythm pickup), no sound is produced , (other than accoustic). However when in position 4 and using both the pickup selector switch and individual volume controls both pickups can be made to independantly produce sound through the amplifier. The rotary switch was replaced when I took it in for repair, as we thought it was the problem, but the same condition still exists after replacement. They sent the board out to an electronics firm and they checked it using the schematic, and apparently everything on it checked out okay.

brian · Post by **brian** » Wed Apr 07, 2004 5:09 am

Here are the links for:

Operating instructions
http://www.rickenbacker.com/us/ltd-kay.htm

schematic
http://www.rickenbacker.com/us/19503.htm

doctorwho · Post by **doctorwho** » Wed Apr 07, 2004 7:22 am

Brian, I know this is a stupid question, but have you replaced the battery with a fresh one to make sure it's not the battery at fault?

My 381JK sustained a broken pickguard (and case) during shipping, and the rotary switch ("the fifth knob") was the "point of impact". I have noticed that the rotary switch can be contrary, cutting out if I don't turn it just so at some settings (which ones, I don't remember), I'll dig the guitar out of the closet and check it more thoroughly, maybe it's a similar problem to yours.

brian · Post by **brian** » Wed Apr 07, 2004 8:01 am

Thanks, Gary any help appreciated. Yes I have changed the battery a couple of times. But the active part works fine, the guitar is in passive mode on this setting. This is a new switch, although was ordered in and looks like the original to me. All other settings but this one work fine. I did try to clean the original switch and see if I could get it to work before I took it in , but no luck. The repair person I took it to was highly recommended by a number of people including some local professional musicians who use him. He had a technician from an associated company which deals with fairly sofisticated electrical equip look at it with the schematic, but they didn't see anything immediate and he is reluctant to spend any more time on it. I guess he doesn't feel comfortable with creating a large bill for me, which I find very commendable and appreciate.
I do have two of these, but the other one which works fine is in mint condition and very low use. While I could try switching the boards I am reluctant to do so as my electrical knowledge is limited and I am afraid that whatever is wrong could ruin the board of the guitar which is working. I know you have be very careful with electrical components which is why I took it to have repaired.

miguel · Post by **miguel** » Wed Apr 07, 2004 12:34 pm

Excuse me for asking such a basic question, but... Have Rickenbackers a battery installed? I´m just familiar with the 300 line.

brian · Post by **brian** » Wed Apr 07, 2004 1:22 pm

There are three models with batterys that I am aware of. The 381JK, 370RM and 380LPZ.

miguel · Post by **miguel** » Thu Apr 08, 2004 12:06 am

Uff, thanks Brian, I was starting to believe that the 330 and the 370/12 had batteries, too.

brian · Post by **brian** » Wed May 05, 2004 8:55 am

I would like to thank Dave Harmon for providing me with a lot of help on this problem. With much effort from him I think we have isolated the problem on my guitar. I was going to wait to thank him until I received the part I need to fully test the solution, but it looks like it may take some time for that to happen, so I will thank him now. I will post an update later when I "implement" the solution

360dave · Post by **360dave** » Wed May 05, 2004 10:15 am

Brian....you are quite welcome.

Considering that you actually understood my voo doo electronics email messages and you actually found the problem after you paid a professional to unsuccessfully repair that beautiful JK......
You did damned well.

Congrats!