help troubleshooting HH strat schematic

[zirltzn]

recently soldered this together (see image attachment).

the problem i'm looking to fix is with S-1 down, positions 1 or 5 the sound is terribly weak. i mean barely audible compared to 2,3,4 with S-1 down.

i'm posting here hoping someone can take a look at schematic to see if all is well there. if so, then its user error with soldering i guess. in that case i'm asking what points to test with multimeter to see if i can find the problem.

it may be just a weak solder, but i need some help in troubleshooting this please.

tia
wb


[these are the options this schematic provides]

S-1 Up

1). Bridge
2). Middle & Bridge (Parallel)
3). Neck & Bridge (Parallel)
4). Middle & Neck (Parallel)
5). Neck

S-1 Down

1). Middle & Bridge (Series)
2). Middle & Bridge (Parallel with Neck n Series)
3). Neck & Bridge (Series)
4). Middle & Neck (Parallel with Bridge n Series)
5). Neck & Middle (Series)

[JohnH]

There are two multimter tests you can do, just plugging into the jack, without going inside.

Measure resistances using a 20k ohms scale, with all knobs at max, stepping through all 10 switch settings. This will measure the pickup resistances, reduced by a few % because the volume pot is in parallel. So you can read the three individual values in position 1,'3 and 5 and see if the series settings are approximately the sum of the relevant ones. Positions 2and 4 in s1 down mode are two in parallel, all in series with a third. Eg, if you had three 6k pups, this would read 9k approx. Positions 1, 3 & 5 have two in series, so 12k ish.Post the readings if you like, and if yoh know the volume pot ohms, these approx comparisons can be back-figured to make them more exact.

The other test is to check that all pickups are in phase in all settings. See the 'screwdriver pulloff test' in the reference section.

[zirltzn]

Sept 23, 2014 16:43:25 GMT -5 JohnH said:

There are two multimter tests you can do, just plugging into the jack, without going inside.

Measure resistances using a 20k ohms scale, with all knobs at max, stepping through all 10 switch settings. This will measure the pickup resistances, reduced by a few % because the volume pot is in parallel. So you can read the three individual values in position 1,'3 and 5 and see if the series settings are approximately the sum of the relevant ones. Positions 2and 4 in s1 down mode are two in parallel, all in series with a third. Eg, if you had three 6k pups, this would read 9k approx. Positions 1, 3 & 5 have two in series, so 12k ish.Post the readings if you like, and if yoh know the volume pot ohms, these approx comparisons can be back-figured to make them more exact.

The other test is to check that all pickups are in phase in all settings. See the 'screwdriver pulloff test' in the reference section.

thanks for the reply.

i just put the MM leads to the other end of the cable/jack (+/-) to read these settings?

S-1 vol pot is 500k ohm

i'll post results shortly.


sorry for delay i though i had "email notice" set.

[newey]

i just put the MM leads to the other end of the cable/jack (+/-) to read these settings?

Yes. Try to avoid using your fingers to hold the probes to the plug, as the conductivity of your skin can affect the readings.

Here's the original post on this testing, per ChrisK:

guitarnuts2.proboards.com/thread/3194/discerning-lp-type-resistances

Chris originally titled the thread "brain scanning through a nostril", but then retitled it as "Discerning Strat-type resistances" to be more descriptive (albeit less comical . . .). The link above is to his similar thread, applicable to HH guitars (like an LP, hence the title).

[ashcatlt]

1) We don't really need to get as far into it as chrisk went with these things. The V pot isn't really going to affect the readings enough to keep us from seeing a major fault.

B) Whatever the title says, the diagram shows HHH with a single volume. With S1 up, it's very much like a standard strat, except for #3. If we really wanted precise measurements of the components, we'd use the Strat-type version of the brain scan through a nostril.

[zirltzn]

ok John & others, here is what my MM returned ...

with all knobs on 10 and MM set at 20k ohms:

5). == neck (switch up)
1). == bridge (switch down)

[S-1 up]

5). 5.86
4). 5.86
3). 2.97
2). 5.91
1). 5.91


[S-1 down]

5). 1__.__
4). 11.58
3). 11.58
2). 11.58
1). 1__.__


with S-1 down readings at positions 5 & 1 only displayed a "1__.__" at 20k ohms ("__" == space). setting MM at 2000k ohms it reads 360

and it is those two positions i get barely an audible tone.


well, there ya go. i'll await you folks reply for interpretation of these reading results. is it the wiring design? my soldering needs tracing? ??

[zirltzn]

Sept 29, 2014 15:39:30 GMT -5 newey said:

i just put the MM leads to the other end of the cable/jack (+/-) to read these settings?

Yes. Try to avoid using your fingers to hold the probes to the plug, as the conductivity of your skin can affect the readings.

Here's the original post on this testing, per ChrisK:

guitarnuts2.proboards.com/thread/3194/discerning-lp-type-resistances

Chris originally titled the thread "brain scanning through a nostril", but then retitled it as "Discerning Strat-type resistances" to be more descriptive (albeit less comical . . .). The link above is to his similar thread, applicable to HH guitars (like an LP, hence the title).

great! thanks for the link.

[JohnH]

Sept 30, 2014 12:57:08 GMT -5 zirltzn said:

ok John & others, here is what my MM returned ...

with all knobs on 10 and MM set at 20k ohms:

5). == neck (switch up)
1). == bridge (switch down)

[S-1 up]

5). 5.86
4). 5.86
3). 2.97
2). 5.91
1). 5.91


[S-1 down]

5). 1__.__
4). 11.58
3). 11.58
2). 11.58
1). 1__.__


with S-1 down readings at positions 5 & 1 only displayed a "1__.__" at 20k ohms ("__" == space). setting MM at 2000k ohms it reads 360

and it is those two positions i get barely an audible tone.


well, there ya go. i'll await you folks reply for interpretation of these reading results. is it the wiring design? my soldering needs tracing? ??

I reckon all of those are consistent with the notion that the M pickup is not getting connected for some reason. In the S1 up settings, positions 2 and 4 should be similar to 3, as two pickups combine in parallel for a lower resistance. But instead, they are the same as the nearby B or N settings, suggesting M is not being connected.

In S1 down mode, all pickups in a series chain need to be connected, or else there is no connection. That is what we see in positions 1 and 5 where M is in series with others. In these settings you are only reading the much higher resistance of the volume pot alone. Once M is taken out, positions 2, 3 and 4 are all the same, which is what you see there.

On the, diagram, it looks to me that the M hot, which goes to the top right switch pole, is only involved in positions 1 and 2. Is that your diagram?  

[zirltzn]

Sept 30, 2014 14:44:19 GMT -5 JohnH said:

Sept 30, 2014 12:57:08 GMT -5 zirltzn said:

ok John & others, here is what my MM returned ...

with all knobs on 10 and MM set at 20k ohms:

5). == neck (switch up)
1). == bridge (switch down)

[S-1 up]

5). 5.86
4). 5.86
3). 2.97
2). 5.91
1). 5.91


[S-1 down]

5). 1__.__
4). 11.58
3). 11.58
2). 11.58
1). 1__.__


with S-1 down readings at positions 5 & 1 only displayed a "1__.__" at 20k ohms ("__" == space). setting MM at 2000k ohms it reads 360

and it is those two positions i get barely an audible tone.


well, there ya go. i'll await you folks reply for interpretation of these reading results. is it the wiring design? my soldering needs tracing? ??

I reckon all of those are consistent with the notion that the M pickup is not getting connected for some reason. In the S1 up settings, positions 2 and 4 should be similar to 3, as two pickups combine in parallel for a lower resistance. But instead, they are the same as the nearby B or N settings, suggesting M is not being connected.

In S1 down mode, all pickups in a series chain need to be connected, or else there is no connection. That is what we see in positions 1 and 5 where M is in series with others. In these settings you are only reading the much higher resistance of the volume pot alone. Once M is taken out, positions 2, 3 and 4 are all the same, which is what you see there.

On the, diagram, it looks to me that the M hot, which goes to the top right switch pole, is only involved in positions 1 and 2. Is that your diagram?  

not mine. i paid a web guitar electronics site to do it for those options. i asked them for 2 weeks to help a bit but never heard back so i posted it here. ;-)

i had seen a schematic on phosenix for nashville-X switching and liked it. that schematic showed two wires to each pickup and my pups have 3-wire. i wasn't sure how to "transcribe" the 2-wire to a 3-wire setup so i asked that guitar website to draw one up for me. that's how that schematic came about.




you are right as to where that M hot wire goes. i see that too though i'm not too good with what positions that involves.

so its the M pickup that has a wire shorted or is that schematic off a bit? would that be the point of failure here? since we now know those values, is the M wiring were i should look when i take the harness out and check?



i'll attach the link to the phostenix image and you can see it.

phostenix schematic


really great info and help. thanks much for your time and expertise.

[JohnH]

The way the M is misbehaving suggests that it is not connected ie open circuit or with a broken wire, rather than shorted out.

Phostenix' diagrams are high standard. And i see his does what you want, and it is quite different to the one you posted. All you probably have to do to use P's diagram is to wire it up ignoring the shield wires, and take all the shields to ground on a pot back

[zirltzn]

Oct 1, 2014 3:15:34 GMT -5 JohnH said:

The way the M is misbehaving suggests that it is not connected ie open circuit or with a broken wire, rather than shorted out.

Phostenix' diagrams are high standard. And i see his does what you want, and it is quite different to the one you posted. All you probably have to do to use P's diagram is to wire it up ignoring the shield wires, and take all the shields to ground on a pot back

ok, now time to take the harness out and check it.

if it isn't that M wire simply needing a solder touch up or similar i'll get a new S-1 and maybe a new super switch and do it P's way and your way by solder the shielding wires to back of pot (S1 in this case as i'm using bourne tone pots or i guess i could ground to one of the bourne lugs that come with them.

looks like i could have saved some trouble and money coming here first with this ;-) no matter i keep learning stuff

many thanks for everyone's, especially JH's help. i'll report back whether it was the loose wire or i built the Phostenix harness

[zirltzn]

i found no loose wires. soldering connections looked good.

i'm gonna go with P's design. these are lawrence blades so just running the chassis wire to pot ground will work as you say? that's what i read so i'm going for it.

[JohnH]

Ok, my last comment had a 'probably' in it. So do you have a link to the pickups that you have so we can check that?

[zirltzn]

Oct 5, 2014 15:14:30 GMT -5 JohnH said:

Ok, my last comment had a 'probably' in it. So do you have a link to the pickups that you have so we can check that?

www.wildepickups.com/Wilde_Bill_s_Twin_Blades.html

[JohnH]

Oct 23, 2014 21:59:49 GMT -5 zirltzn said:

Oct 5, 2014 15:14:30 GMT -5 JohnH said:

Ok, my last comment had a 'probably' in it. So do you have a link to the pickups that you have so we can check that?

www.wildepickups.com/Wilde_Bill_s_Twin_Blades.html

I looked through that link but didn't find what I was after. Most probably, the bare wire is separate from the two coil wires, and then it will work with phostenix' diagram as described. I just wanted to check that it is not internally connected to a coil wire which would not be an issue in most wirings but would be so in series wiring. You could check with a meter, to see if you can read the coil resistance between the coil wires, and then have infinite resistance from bare to either coil wire. Or just build it and see.

[zirltzn]

Oct 24, 2014 14:29:02 GMT -5 JohnH said:

Oct 23, 2014 21:59:49 GMT -5 zirltzn said:

www.wildepickups.com/Wilde_Bill_s_Twin_Blades.html

I looked through that link but didn't find what I was after. Most probably, the bare wire is separate from the two coil wires, and then it will work with phostenix' diagram as described. I just wanted to check that it is not internally connected to a coil wire which would not be an issue in most wirings but would be so in series wiring. You could check with a meter, to see if you can read the coil resistance between the coil wires, and then have infinite resistance from bare to either coil wire. Or just build it and see.

finally got it wired. made a the changes according to the phostenix diagram. works like a charm. really sweet sounding with a few options to give her some "ump" when/if needed. sorry for the long time in between reply. i'm way too slow these days.

appreciate all the help.