BassTractor Posted September 16, 2014 Share Posted September 16, 2014 Anyone know what the quickest fix would be? I see: 1) metal glue to glue the 2mm or so thin part of the pot shaft back on the pot. I'd use vaseline on those parts that must not get glue on them. Requires a rig for placing the shaft semi-perfectly over the pot. 2) stainles steel "rod" glued into both parts. This would require drilling a 1mm or 1.5mm hole in the pot part of the shaft as well as in the thick part of the shaft, and glueing in a fitting stainless steel bit into them. I can easily mount the thick part of the shaft in a vertical bench drill with clamping system, but may have trouble mounting the body perfectly horizontal. 3) soldering in the new pot (or whatever method is required). This seems like the easy solution, but someone warned me against it, as reportedly these preamps are not that easily serviceable as one might assume. Before I put the bass on the operating table and remove its innards, can someone give a heads up on the preferred method? Quote Link to comment Share on other sites More sharing options...
KiOgon Posted September 16, 2014 Share Posted September 16, 2014 I'd say a new pot is the only way! You could spend hours faffing with glue & bodges Quote Link to comment Share on other sites More sharing options...
Bolo Posted September 16, 2014 Share Posted September 16, 2014 Any good fix would require the pot to be removed from the body I think. In the hobby of converting war gaming miniatures it is quite common to use the tiny drill and wire method, although those objects never have any torque applied to them. The safest way I recon is to replace the whole pot. If you feel your soldering skills are not up to snuff perhaps there is a skilled electrics enthusiast near you? Quote Link to comment Share on other sites More sharing options...
brensabre79 Posted September 16, 2014 Share Posted September 16, 2014 [quote name='KiOgon' timestamp='1410861559' post='2553898'] I'd say a new pot is the only way! You could spend hours faffing with glue & bodges [/quote] +1 Quote Link to comment Share on other sites More sharing options...
paul_5 Posted September 16, 2014 Share Posted September 16, 2014 +1 for replacement pot - bodge jobs and 'temporary' fixes (particularly electronics) have a way of becoming permanent, and you'll find out that they fail at the worst possible moment. Quote Link to comment Share on other sites More sharing options...
thefyst Posted September 16, 2014 Share Posted September 16, 2014 yeah id just replace the pot also... allthough cant find any decent images of the pots but they look like they have extended lugs that go straight into a board...might be tricky to replicate with a standard pot. Quote Link to comment Share on other sites More sharing options...
Dad3353 Posted September 16, 2014 Share Posted September 16, 2014 Quickest..? A pin inserted into a cork, then heated to 'melt' into the plastic shaft on the instrument. Best..? Open the instrument, remove the pre-amp board and replace the pot, or give it to someone competent. KiOgon is the top man for doing this kind of work; other repairmen are available. Good luck, either way. Quote Link to comment Share on other sites More sharing options...
BassTractor Posted September 16, 2014 Author Share Posted September 16, 2014 (edited) Thanks guys! I went out and bought the tools necessary to get this dismantled (I think it's Imperial stuff), and you know what: replacing the pot seems like a doddle. Several methods are available, and I just need to count the amount of wires I'll have to desolder and solder for each method. For those interested: two and two pots are mounted sideways - directly on tiny circuit boards (with the three pins through the board) that are anchored only on those two pots, meaning I can center the pots in the pot holes and the circuit boards will follow, so there are no special requirements for placement of the pots on the boards other than that I must keep their shafts parallel to each other. I might remove just one of those boards or both or even the whole pre-amp constellation, depending on what I think is easiest. The guy warning me seems to have had little reason to. Like KiOgon says, I could spend hours building small rigs and stuff. Seems quite unnecessary now. Thanks again! Edited September 17, 2014 by BassTractor Quote Link to comment Share on other sites More sharing options...
BassTractor Posted September 16, 2014 Author Share Posted September 16, 2014 [quote name='thefyst' timestamp='1410886032' post='2554341'] yeah id just replace the pot also... allthough cant find any decent images of the pots but they look like they have extended lugs that go straight into a board...might be tricky to replicate with a standard pot. [/quote] Thanks, Thefyst. I saw your post after writing mine (laptop battery trouble). Yup, the pots are a mini type with rectangular body, and three pins coming out from their sides. Trying to use a standard pot here, while probably doable, would require one side of one or two mini circuit boards to be moved out of its way, and there is not that much space, so I think it's is better avoided. I do have the correct pot for it, so no sweat. Dad: I think they're brass shafts, but thanks! Quote Link to comment Share on other sites More sharing options...
flyfisher Posted September 16, 2014 Share Posted September 16, 2014 A bit late to this but I think you've chosen the best repair method. Mechanical repairs of such small components are rarely as robust as the original and you have to question why it broke in the first place. As you've said the pots 'legs' are soldered directly to the circuit board, I would suggest cutting the legs to remove the pot first. Then you can easily desolder each pin individually, pulling it out of the circuit board using thin pliers (or tweezers etc) before. This is a much faster method than trying to remove solder from around 3 'legs' and freeing them all up so the intact pot can be removed - and in these cases, fast is good because you don't want to apply heat for too long otherwise you'll likely lift the copper tracks off the circuit board and then you're getting deeper into even trickier repair territory. Photos of the intact pots before you start removing them can also be very helpful when soldering in the new ones. Good luck! Quote Link to comment Share on other sites More sharing options...
Dad3353 Posted September 16, 2014 Share Posted September 16, 2014 [quote name='BassTractor' timestamp='1410890125' post='2554413']... Dad: I think they're brass shafts, but thanks! [/quote] [sharedmedia=core:attachments:167485] I'm not sure I want to know how the brass shaft got busted..! [size=4] [/size] Quote Link to comment Share on other sites More sharing options...
BassTractor Posted September 16, 2014 Author Share Posted September 16, 2014 Thanks, Flyfisher! The shop who sold me the bass had possibly assumed the Music Man cases are sturdier and tighter than they really are, and had omitted to pack the bass inside the case. Also, they had omitted to fill the void between the case and the way too wide outer currugated board box. So the bass moved freely about and got the case lid to flex, and the volume pot knob was knocked off by the case innards. As said, the pot shaft is brass and just a few mm in diameter where it enters the pot body. Dunno whether the normally visible thick part of the shaft is in one piece with the thin part of it, but it makes no difference for the repair methods that were contemplated. BTW, I could've sent it back, but chose to be friendly with the seller, and do the repair myself. Thanks for the words on soldering technique. I've soldered electronics a lot before, as a hobby, but haven't done it that much the last few decades - only when necessary. Still got good gear for it, so the bottleneck is me. Quote Link to comment Share on other sites More sharing options...
thefyst Posted September 16, 2014 Share Posted September 16, 2014 any chance of some decent photos of the preamp? im kinda interested Quote Link to comment Share on other sites More sharing options...
icastle Posted September 16, 2014 Share Posted September 16, 2014 Another +1 for replacing the pot. Bodge jobs are fine when you've no other options available but using them as a matter of course is just saving up a disaster for later. Quote Link to comment Share on other sites More sharing options...
BassTractor Posted September 17, 2014 Author Share Posted September 17, 2014 [quote name='thefyst' timestamp='1410906277' post='2554668'] any chance of some decent photos of the preamp? im kinda interested [/quote] Will try in daylight tomorrow. Quote Link to comment Share on other sites More sharing options...
Bolo Posted September 19, 2014 Share Posted September 19, 2014 Make it a video tutorial Quote Link to comment Share on other sites More sharing options...
BassTractor Posted September 27, 2014 Author Share Posted September 27, 2014 Here are them pics. Sorry for their belatedness, or rather my belatedness in taking them: [URL=http://s1170.photobucket.com/user/basstractor1/media/IMG_1230_zpsd0485cda.jpg.html][IMG]http://i1170.photobucket.com/albums/r525/basstractor1/IMG_1230_zpsd0485cda.jpg[/IMG][/URL] [URL=http://s1170.photobucket.com/user/basstractor1/media/IMG_1232_zpsaf1d8eab.jpg.html][IMG]http://i1170.photobucket.com/albums/r525/basstractor1/IMG_1232_zpsaf1d8eab.jpg[/IMG][/URL] [URL=http://s1170.photobucket.com/user/basstractor1/media/IMG_1233_zps4ba1bf2b.jpg.html][IMG]http://i1170.photobucket.com/albums/r525/basstractor1/IMG_1233_zps4ba1bf2b.jpg[/IMG][/URL] Quote Link to comment Share on other sites More sharing options...
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