Gibson RD Artist Bass---Moog Electronics inside..not working

[nevetslab]

I read in the links I provided in the initial post they changed from this Switchcraft 3-pole/3-way switch that it proved to be unreliable, and changed to a pair of small sealed toggle switches.

[nevetslab]

Found the problem this morning. It WAS the Function Switch that I had to tear down, clean & rebuild. The inner Wiper terminal, which takes the Bass Pickup on the Normal Contact (mid-position) wasn't making contact, even though it sure looked like it was. I had to re-tension the contact so it was reliably making contact, which restored the Neck Pickup in the Middle and Forward Positions. I had it backwards...thinking the Compressor/Expander position was the Forward position. It wasn't...it was the Rear Switch position. It sure sounded like it was getting those functions, which I was.

Before I made that discovery on the switch contact, I again opened up the PCB and swapped out the three caps that had been 0.47uF/50V Electrolytics, and I had replaced them with 1uF NP's...I pulled those out and put in 0.47uF Film caps..Panasonic ECQV series. Then replaced the last two Electrolytic's I had left in place, so now all of the Electrolytics are new. I did just order CD4007's and TL022CP's, but won't need them, having found the fault with the switch.

So....EVERYTHING WORKS!! AWSOME SOUNDING BASS!!

Yesterday I did install a nylon #4-40 Standoff, drilled a hole for tapping #4-40 into the body, cut the head off of a #4-40 screw and applied glue to the base of the standoff, drove in the #4-40 stud, then threaded it into the body, so the front end of the long PCB has a support standoff that it never had...though there was a screw hold there. Too close to the Xstrs there, which led to using Nylon screw and standoff.



Views of the PCB assy with the new connectors & capacitors in place.





Figures the problem that seemed like a leaky cap, having the neck pickup for a few minutes, then nothing, and that repeating itself a couple times, until it stopped all together in those two switch positions would be something stupid. Looked solid, and I had 0 ohm continuity prior to re-wiring the switch and putting it back into place. No regrets, though. Replacing the connectors thruout, replacing the aged electrolytic caps thruout puts new life into this fine Gibson Bass.

Plays a lot easier than my early 60's Fender Precision bass!

[nevetslab]

Yesterday the owner of this Gibson RD Artist Bass came by to pick it up. After plugging it into the Ampeg SVT-CL amp/cabinet, seeing his face light up with hearing everything working, and the wide range of character the Moog Preamp renders, now with fresh contacts & caps sure made all the effort it put me thru worth while!