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Rossc0
01-07-2017, 08:54 AM
I managed to get hold of an Amp from my daughters boyfriend today and plugged the beast in for the first time.

Good News, on the bridge pickup, whisper to a scream..very happy, huge amount of variation across the volume and tone controls, absolutely no unwanted hum, couldn't have asked for more.

Bad news, on the neck and in the middle of the 3 way switch, nothing, dead. :(

All my earths appear good, I've triple checked the wiring diagram and everything is going where it should.

Without ripping everything apart just yet, where would you suggest starting to hunt down the issue?

I do have a very simple multimeter, nothing fancy.

Cheers

Brendan
01-07-2017, 10:21 AM
Rossc0 - if you can give us a couple of photos of the wiring, couple of the guys here are sleuths in finding issues.

Rossc0
01-07-2017, 10:51 AM
Links to enable full size image, although its hard to see anything institute

https://1drv.ms/i/s!AkGEvZc81PxrmhVOM00CCfuawjQx

https://1drv.ms/i/s!AkGEvZc81PxrmhZWb5RMo6eW1ZPY

Cheers

Rossc0
01-07-2017, 11:45 AM
wiring diagram. there is an earth from bottom tab of neck tone that's not shown here.

http://www.buildyourownguitar.com.au/forum/attachment.php?attachmentid=17462&d=1487735048

WeirdBits
01-07-2017, 12:18 PM
First guess would be a short between the neck hot and the copper shielding somewhere, thus killing your signal in the middle and neck positions. This often happens with copper shielding and recessed pots where the underside (or part) of the hot lug(s) brushes a high spot of the copper. Very common.

Set your multimeter to resistance/Ohms and test between ground/shielding and the neck's volume & tone pot hot lugs (with the pots at max/10). If you get little to no resistance then something is shorting. Repeat the process with the bridge pickup (with the toggle in the bridge position) to double-check. If it is a short then start checking for lugs shorting or a stray wire strand touching somewhere etc.

I often put insulating tape on top of the copper shielding beneath where the pot lugs will sit to prevent any chance of a short.

Rossc0
01-07-2017, 12:20 PM
Cheers, will give that a go. Beginning to regret using the shielded cable, so many ways to have an erroneous earth.

FrankenWashie
01-07-2017, 01:49 PM
First guess would be a short between the neck hot and the copper shielding somewhere, thus killing your signal in the middle and neck positions. This often happens with copper shielding and recessed pots where the underside (or part) of the hot lug(s) brushes a high spot of the copper. Very common.

Set your multimeter to resistance/Ohms and test between ground/shielding and the neck's volume & tone pot hot lugs (with the pots at max/10). If you get little to no resistance then something is shorting. Repeat the process with the bridge pickup (with the toggle in the bridge position) to double-check. If it is a short then start checking for lugs shorting or a stray wire strand touching somewhere etc.

I often put insulating tape on top of the copper shielding beneath where the pot lugs will sit to prevent any chance of a short.

That's a great tip WeirdBits, I would not have thought to insulate under the lugs. I may execute that as a standard.

Rossc0
01-07-2017, 03:36 PM
Woohoo sorted. the middle lug on the neck volume was shorting to earth. Think there was a few strands of the cable shielding caught up in the solder connection. happy days.

FrankenWashie
03-07-2017, 01:42 PM
Woohoo sorted. the middle lug on the neck volume was shorting to earth. Think there was a few strands of the cable shielding caught up in the solder connection. happy days.

Result! good sleuth work Rossc0.