513 Bridge Pickup Dropout

[David Gibson]

The bridge pickup on my 513 drops out in both the single coil and heavy humbucking modes only when just the bridge pickup is selected. The clear hum bucking position works just fine.

Any suggestions on what the problem might be?

Thanks for the help.

 

[Dusty Chalk]

It's probably a connection problem on the PCB -- that is the first, most likely problem on any dropout problems on a 513 with PCBs.

 

[David Gibson]

So I checked for continuity from the 3-way switch to each connection on the PCB and have good continuity on each. Then checked from each connection on the 3-way to the mini sockets where the pickups plug into the PCB. Have good continuity at each also. So all connections on the PCB would seem to be OK.

Since the problem is isolated to the bridge pickups, is there another PCB behind the bridge pickup?

Yea I know, I should look for myself.

 

[Dusty Chalk]

Yes, I believe there should be another PCB on which the bridge pickup is mounted.

 

[David Gibson]

So I pulled the bridge pickup tonight. Have continuity from each wire off the coils to the soldered connection on the PCB on the back of the pickup. I also have continuity from the soldered connections on the pickup PCB all the way back to the 3-way switch. I sprayed electrical contact cleaner on the 3-way. All for no good. The bridge pickup still drops out in full humbucking and single coil. A-OK in light humbucking.

At a loss on what the problem could be.

 

[aPeRSon]

So I pulled the bridge pickup tonight. Have continuity from each wire off the coils to the soldered connection on the PCB on the back of the pickup. I also have continuity from the soldered connections on the pickup PCB all the way back to the 3-way switch. I sprayed electrical contact cleaner on the 3-way. All for no good. The bridge pickup still drops out in full humbucking and single coil. A-OK in light humbucking.

At a loss on what the problem could be.

I think it's worth flexing the PCB that the coils are mounted on, to make sure that there's no signs of the bobbins being loose. I had a very similar issue and it turned out that the small amount of uneven flexing that took place whilst I was setting my pickup heights had caused two of the connection to become loose, giving me very similar (and intermittent) symptoms. I appreciate that you've checked for continuity already, but it could be that you have good contacts while the pup is on the bench, but the connection(s) might be cutting out when the pup is re-mounted and under spring tension in the guitar.

In my case, I ended up squeezing the coils onto the PCB whilst I dabbed each of the connections with a soldering iron. With the contacts re-made, I never had a problem again.

Just be careful whenever you touch the pickup height / mounting screws - work in pairs (both treble sides or both bass sides) to avoid any twisting of the PCB.

 

[bodia]

I think it's worth flexing the PCB that the coils are mounted on, to make sure that there's no signs of the bobbins being loose. I had a very similar issue and it turned out that the small amount of uneven flexing that took place whilst I was setting my pickup heights had caused two of the connection to become loose, giving me very similar (and intermittent) symptoms. I appreciate that you've checked for continuity already, but it could be that you have good contacts while the pup is on the bench, but the connection(s) might be cutting out when the pup is re-mounted and under spring tension in the guitar.

In my case, I ended up squeezing the coils onto the PCB whilst I dabbed each of the connections with a soldering iron. With the contacts re-made, I never had a problem again.

Just be careful whenever you touch the pickup height / mounting screws - work in pairs (both treble sides or both bass sides) to avoid any twisting of the PCB.

This is good advice. A cold solder joint would exhibit the issue you're having, and can be tricky to diagnose.

 

[David Gibson]

All great advice. Tried the suggestion of dabbing the PCB/coil connections while squeezing the two together. No luck.

Bummed over the idea of sending off to PTC for an indefinite period of time for repair.