avengers63 Posted February 13, 2009 Report Share Posted February 13, 2009 I'm finishing up a guitar today, and the wiring is a shade off. 2HBs, LP-style wiring. With the 3-position in the middle, the neck pup works. With the switch in the neck position, it's dead. This one makes -ZERO- sense to me. Any advice? Quote Link to comment Share on other sites More sharing options...
psw Posted February 13, 2009 Report Share Posted February 13, 2009 if it is a gibson threeway style, the leaf springs sometimes don't make adequate contact...although this doesn't seem to completely explain things...it can often happen if it is very tight in the cavity and/or there is sheilding which can short out a position when the leaf springs move. Seeing if the switch will work when unscrewed and hanging out of the cavity can sometimes identify these problems. Whith cheap switches, sometimes you may need to gently bend the switch leaf a little...but don't do this unless you have identified this as the problem as they can be a little sensitive and fail to release. Usually there are 4 soldering tabs and a ground at the rear, the two centre tabs are generally joined as the hot...a couple of months ago, someone had the common ground and hot tabs reversed...again doesn't sound like the problem here either. It sounds as if the neck position pickup isn't working and it could be something wrong down the line at the controls perhaps...I assume in the bridge position, the bridge pickup is working, in the middle position the bridge pickup is working....in which case the leaf springs and some kind of short may well be the problem. A very similar thing happened on my tele in part due to the tight spacing, and the wires in there getting in the way of the switch movement. Quote Link to comment Share on other sites More sharing options...
avengers63 Posted February 13, 2009 Author Report Share Posted February 13, 2009 That's what's really weird about this. The bridge works fine. The neck works when the switch is in the center, but not when only the neck is selected. That it would work in one position and not in another is what's confusing about it. Quote Link to comment Share on other sites More sharing options...
psw Posted February 13, 2009 Report Share Posted February 13, 2009 It sounds like the leaf spring on the neck pickup is not releasing (depending on the switch design) or connecting which is usually a physical problem, often caused by it hitting the wall of the cavity, or a stray wire...or a cheap switch in which the leaf spring needs to be closed or opened up ever so slightly. Pushing the spring over may identify this and a solution or the problem become apparent. Don't bend things around too much though as you may create the opposite problem and you can't get the neck pickup off! You could perhaps test the switch contacts with a multimeter to see if and when things are connecting...good luck...welcome to the frustrations of wiring! pete Quote Link to comment Share on other sites More sharing options...
avengers63 Posted February 13, 2009 Author Report Share Posted February 13, 2009 Alright - one down and another jumps up. Actually, the second was there all along, but I failed to notice it somehow. The neck works now. I honestly don't know what I did, and I'm not looking into it too hard. If it works, that's good enough. Now, there's a significant buzz. It stops when I touch the cable. Not the strings, bridge, etc... the metal plug of the cable. On the good side, I REALLY like these pups. They have a hardcore s/c twang to them. They're really bright. Quote Link to comment Share on other sites More sharing options...
psw Posted February 14, 2009 Report Share Posted February 14, 2009 Check the string ground is connecting properly...use a multimeter perhaps from a place where the buzzing stops to the strings and other part's to see what is grounding... what Pups are there...the retrotron or something? Quote Link to comment Share on other sites More sharing options...
avengers63 Posted February 14, 2009 Author Report Share Posted February 14, 2009 what Pups are there...the retrotron or something? Nah... it's the leopardwood capped Avenger. I got some cheap pups from a Canadian eBay seller. How about a quick tutorial on how to set & use my multimeter to search? It's a cheap-o with a dial & needle. Quote Link to comment Share on other sites More sharing options...
psw Posted February 14, 2009 Report Share Posted February 14, 2009 It's a cheap-o with a dial & needle Lucky you...although perhaps not as "accurate" to read for electronics work (you need to make sure you keep recalibrating it to zero...touch the two probes together on a resistance reading and turn the dial till it reads zero, for accurate work, do this before measuring anything and especially when changing scale), these things can be great for guitar work...even better than a digital reader! In this application, check the meter by touching the two probes, you will see the needle jump. Now, You could touch the round of the jack which seems to be grounded (or you would hope so) and indicated by the sudden loss of buzz when touched. Now, touch the other probe on anything and everything else you may expected to be grounded. In this case, the strings first of all...the bridge ground sounds like it is not connecting properly. If it is connected, you would expect the needle to jump...if not, it wont! It is difficult to test such simple continuity issues with a digital meter. You can use it to test the value of a pickup...you may need to select a scale of resistance of thousands of ohms...touching the two leads of a coil, or pickup will show the resistance of it showing that the coil is in tact...a digital meter will be easier to read with definitive results in figures, but the fact that there is a reading at all is easier to see with an "analog" meter (ie needle). However, on a low voltage scale (V) if you attach it to a pickup coil and tap it with a screwdriver, you can see the needle jump as the signal of the strike causes the needle to jump (it may attempt to jump backwards, this can be corrected by swapping the leads). This is useful for identifying which leads belong to which coil in a 4 wire HB for instance, or a complex switching system with wires everywhere. The fact that the spike will jump the meter in different directions is also useful, as this indicates the phase of the coil (the relative +/- of the wires) and identify which is which. In an HB, the coils are supposed to be out of phase, because so too are the magnets...working out which is which is important at times. You can also measure whether HB's are wired in series (where the two coil values are added) or parallel (where the two coils combined offer much the same resistance)...an analog meter is perfectly good for this kind of thing also. You can use the voltage scale to work out the voltage of batteries...probably more hygenic than licking them to see if they are any good...hehehe...it will also show how much life is left or even how much current is being drawn in a working circuit...just touch the positive probe to plus and negative to - on the battery...again, an analogue meter gives an instant show that power is present...easier than a digital in some ways (you can see the needle jump out of the corner of your eye) if you just want to know if there is power there at all! You can test pots by measuring resistance...again thousands of ohms on the resistance scale. A probe between the middle and either of the outer lugs will show the resistance...the value of the pot should be the value of the most resistance (full on) and turning it will show the drop (and the audio taper in such a pot) as it is turned...eventually going to zero ohms. You will be surprised at how wide some pots are in value...they are not always as high as rated, often 20% difference...not that it matters a lot! You can test the controls on a guitar by probing the hot and cold jack lugs of a guitar lead plugged into it in a similar way. If pickups are connected, remember you are likely reading their resistance as well and an appropriate scale may need to be selected. A 1k resistance on a 100K+ scale is obviously hardly going to move a needle at all...of course, a 100K resistance on a 1k resistance will really make the needle jump! Many digital readers when a wrong scale is selected will get confused or give you some weird reading that is easy to misinterpret if you don't know what you were expecting and if the question you are asking is simple (eg...are two components are connected... for instance, and most common in this work). In a switch, select a resistance and touch the common (out) hot out, then touch another lug and see the effect of the switch when it is moved. If things are connecting the needle will ground out and go to highest resistance (jump). Touching the ground and a hot lug where there is no sound, usually indicates a short from hot to ground...touch a ground somewhere and the hot and see if you get a continuity jump...look or probe about till you find where this is. On pickups or anything, you need both hot and ground to make a circuit...if no sound it can be a short (hot touching ground) or a break (no hot or ground)...the jumping meter can be the ideal testing tool to see that things are connected and identifying where shorts and breaks occur. Often these problems can not be seen visually...or at least easily. A short of a component against shielding in an obscure place can often not be "seen" and be the source of much frustration ... So...lots of praise for the old analog meters...I have found them difficult to find, certainly cheap ones...but mine is 30+ years old and still going strong even though it is cheap and held together with tape. Digital ones seem to be very cheap, and these can be good, so if you see one pick it up...but count your blessings on the old needle and lend it to know one! pete ps...batteries last a long time (unless you leave them on) which is why you will forget they are there...a very low battery can affect readings, or it can stop working...don't be fooled by this...check the meter if something seems strange. Quote Link to comment Share on other sites More sharing options...
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