Skol303 Posted February 5, 2014 Share Posted February 5, 2014 (edited) I’ve been having trouble with my active Fender Jazz. The batteries have been draining exceptionally quickly - I installed a new set at the start of January and they’re already dead: horrible distortion from the bass, then no signal. Apparently flat. I swapped them for a new set - bass worked fine. To double-check, I reinstalled the ‘old’ batteries from January: again, distortion then fade to black… Keen to remedy this, I’ve just shipped the bass off to Fender for inspection (under warranty). I’ve also just taken delivery of a cheap multimeter (spurred on by this problem) and have tested the ‘old’ batteries just removed from the bass. One measures around 5v, the other around 9v. This seems odd… I was expecting these batteries to be flat as pancakes given the behaviour of the bass with them installed. Now I’m wondering whether:[list] [*]The batteries were in fact fine and someone is spiking my evening tea [*]I don’t know how to use a multimeter properly [*]The problem with the bass is not with the batteries [*]The problem is with the batteries, [i]not[/i] the bass [/list] Can anyone suggest what might be going on? Cheers, Paul Edited February 5, 2014 by Skol303 Quote Link to comment Share on other sites More sharing options...
flyfisher Posted February 5, 2014 Share Posted February 5, 2014 (edited) I've got a fender active Jazz and I've been worrying that the batteries seem to be lasting too long - almost a year now! OK, the amount of actual playing will affect the battery life, but unless you're at it 24/7 then one month sounds like a very short time to me. I wouldn't worry about the distortion. That's just a symptom of the dying batteries underpowering the pre-amp and causing it to distort. If new batteries sound fine, then I wouldn't give that a second thought. My understanding is that the battery is only connected when the lead is plugged in. So make sure you remove it when you're not playing. But I'm guessing you already do that. It's possible that the jack socket contacts are not working correctly such that the battery is remaining connected even when the jack plug is removed. Should be easy to check but you'll need to take things apart. If you're not comfortable with such things then it's a tech job. Perhaps some other active jazz owners could say how much use their bass gets and how long their batteries typically last? Edited February 5, 2014 by flyfisher Quote Link to comment Share on other sites More sharing options...
Skol303 Posted February 5, 2014 Author Share Posted February 5, 2014 ^ Cheers for the reply. My thoughts exactly. What seems odd is that the apparently 'dead' batteries I removed from the bass are showing as being 5v and 9v on the multimeter - I'd expect them to work at those Voltages, yet the bass was distorting and then simply fading to no signal with them installed. Quote Link to comment Share on other sites More sharing options...
Michael J Posted February 5, 2014 Share Posted February 5, 2014 5V [b]is[/b] flat as a pancake for a 9V battery. Quote Link to comment Share on other sites More sharing options...
Skol303 Posted February 5, 2014 Author Share Posted February 5, 2014 [quote name='Michael J' timestamp='1391607704' post='2359104'] 5V [b]is[/b] flat as a pancake for a 9V battery. [/quote] Ah! That's good to know... well, good in that it means there [u]is[/u] a fault with the bass and I'm not going mad Thanks for clarifying. Quote Link to comment Share on other sites More sharing options...
flyfisher Posted February 5, 2014 Share Posted February 5, 2014 [quote name='Michael J' timestamp='1391607704' post='2359104'] 5V [b]is[/b] flat as a pancake for a 9V battery. [/quote] Yep, especially if you're just measuring it with a multimeter and no actual load. Interesting that it's only one battery that is so flat. Might be a clue there, but not sure what. I don't know the pre-amp circuit details, so I don't know what voltage it needs to operate correctly, but 5v is almost certainly much too low. In general, batteries do a pretty good job of maintaining their voltage throughout their operating life, then it quickly drops off. Different types have slightly different characteristics but that's the general principle and one that circuit designers will usually rely on. Again, I wouldn't be worrying about the distorted sound - I think you've found the reason for that. It's what's causing the battery to discharge so quickly in the first place that's the issue. Quote Link to comment Share on other sites More sharing options...
icastle Posted February 5, 2014 Share Posted February 5, 2014 You can't assess battery condition accurately with a multimeter is the other problem. At the very least you need to measure the voltage whilst the battery is under load and even then, you have no idea what the threshold is on the device being powered. EDIT: Beaten to it by Flyfisher Quote Link to comment Share on other sites More sharing options...
Skol303 Posted February 5, 2014 Author Share Posted February 5, 2014 [quote name='flyfisher' timestamp='1391608624' post='2359126']In general, batteries do a pretty good job of maintaining their voltage throughout their operating life, then it quickly drops off.[/quote] [quote name='icastle' timestamp='1391608795' post='2359131']You can't assess battery condition accurately with a multimeter is the other problem. At the very least you need to measure the voltage whilst the battery is under load and even then, you have no idea what the threshold is on the device being powered.[/quote] Cheers guys! This is precisely why I should have listened more closely during physics lessons as a kid I'm obviously peeved that the bass has a fault, but I'm at least reassured that I'm doing the right thing by having it inspected whilst under warranty. I'll update this thread once the story has concluded... [i](cue dramatic music).[/i] Quote Link to comment Share on other sites More sharing options...
icastle Posted February 5, 2014 Share Posted February 5, 2014 9/10 times I've seen this happening it's been either a faulty socket or forgetting to unplug the bass when not in use. Quote Link to comment Share on other sites More sharing options...
Skol303 Posted February 5, 2014 Author Share Posted February 5, 2014 [quote name='icastle' timestamp='1391612608' post='2359215'] 9/10 times I've seen this happening it's been either a faulty socket or forgetting to unplug the bass when not in use. [/quote] Yup, I reckon it's the jack socket or maybe something shorting elsewhere. I'm a fastidious unplugger of gear, so I know for sure it's not that! Quote Link to comment Share on other sites More sharing options...
flyfisher Posted February 5, 2014 Share Posted February 5, 2014 Being under warranty should be good news. Will be interesting to find out the actual problem. Good luck with it! Quote Link to comment Share on other sites More sharing options...
Subthumper Posted February 5, 2014 Share Posted February 5, 2014 Sounds like it's either the Jack socket shorting the battery negative to ground, possibly to the cavity screening, or it has ben wired wrong effectively leaving the pre amp switched on all the time. I made exactly this mistake myself when wiring up one of my basses. Quote Link to comment Share on other sites More sharing options...
Dad3353 Posted February 5, 2014 Share Posted February 5, 2014 Another possibility, although less probable, would be a rogue duff battery. I'd argue that, if the jack switch was permanently 'on', the batteries wouldn't even last a month. A couple of weeks, I'd guess, at best. Maybe just one battery was unwell, and gave up the ghost..? I'd have put in a fresh set and tried again. No harm in getting it checked, though. Just sayin'. Quote Link to comment Share on other sites More sharing options...
Skol303 Posted February 5, 2014 Author Share Posted February 5, 2014 [quote name='Dad3353' timestamp='1391636701' post='2359702']Maybe just one battery was unwell, and gave up the ghost..? I'd have put in a fresh set and tried again. No harm in getting it checked, though.[/quote] Good point Douglas. I did wonder the same... However the batteries it came with were also flat within a few weeks. Now they could have been just old batteries and on their last legs. But when it subsequently flattened the new Duracells I'd installed in January I began to think something is amiss. Plus, I'm simply impatient and want it fixed NOW! Worst case I'll have to pay the courier fee for Fender to tell me that it was a duff battery. But I thought it better to be safe than sorry. I'll let you all know the diagnosis in due course. Thanks again for the input! Quote Link to comment Share on other sites More sharing options...
Dad3353 Posted February 5, 2014 Share Posted February 5, 2014 [quote name='Skol303' timestamp='1391639804' post='2359751']...I'll let you all know the diagnosis in due course...[/quote] You'll do nothing of the sort..! You'll let us know everything NOW..! We, too, are impatient..! ... Quote Link to comment Share on other sites More sharing options...
AngelLaHash Posted February 10, 2014 Share Posted February 10, 2014 Isnt there some Mod you could do so that it Turns OFF fully.. I could hook some thing up via a Volume Pot i guess Hook Ground to the Jack .. If you have a Pickup Selection switch wouldnt take much to replace and put in a off positions maybe Tried to google for the circuit but found so many types and not active ones !! Quote Link to comment Share on other sites More sharing options...
flyfisher Posted February 10, 2014 Share Posted February 10, 2014 I doubt that any mods are needed. Given that the bass shouldn't be chewing through batteries so fast in the first place, it's more likely to be an actual fault, so best to get that fixed, not mod around it. That's my take on it anyway. Quote Link to comment Share on other sites More sharing options...
AngelLaHash Posted February 10, 2014 Share Posted February 10, 2014 for it to be using batteries so much means its making a connection.. I was suggesting a MOD to make sure the Battery wasnt used up..as i said i dont know what design this is .. a LOT of makers of ITEMS make FAULTS built in.. IE fixing Laptops .. noticed a lot of faults with were the PSU plugs in.. because a few laptops dont have any thing bit a 2mm bit of plastic holding back the connection box and nothing behind it.. That is waiting for it to happen Quote Link to comment Share on other sites More sharing options...
flyfisher Posted February 10, 2014 Share Posted February 10, 2014 Yes, it's making a connection but the point is it shouldn't be unless the lead is plugged in. That's a fault and it should be fixed. It's unlikely to be a design fault because my Fender active J doesn't behave that way (nor does my active acoustic guitar) and we've not been inundated with other active jazz owners complaining about the same problem, which also suggests it's a one-off fault. Plus the bass is under warranty, so the supplier should fix the fault anyway. Also, modifying the pickup switch to be centre-off would only disconnect the pickups from the preamp, it wouldn't remove the battery power to the pickup, so wouldn't solve the problem. Even if the bass had a pickup switch, which is doesn't. Quote Link to comment Share on other sites More sharing options...
AngelLaHash Posted February 10, 2014 Share Posted February 10, 2014 (edited) what type of SWITCH do you have for the PICK UP.. 2P2T (on/on/on) well you would need another Pole to be able to change that so the battery is turn off and state 3P4T maybe a rotary as i dont know of a toggle well that one looks like its powering up the PreAmp .. should really go to a Switch first to turn it off...other wise there is Power to the PCB Same with this one but the Negitive side of the battery is going to the Jack plug ground.. tho the grounds dont seem to go to ground but that might compleat the circuit tho I do think its just a short tho Edited February 10, 2014 by AngelLaHash Quote Link to comment Share on other sites More sharing options...
icastle Posted February 10, 2014 Share Posted February 10, 2014 It's not. The -ve supply is connected to Pin 7 which is directly linked to Pin 8. Pin 8 goes to the jack socket where it is switched by inserting a jack plug and then returned to the PCB. It's bog standard active bass switching. Quote Link to comment Share on other sites More sharing options...
flyfisher Posted February 10, 2014 Share Posted February 10, 2014 Yep, nothing wrong with the design, it's just that the bass in question has developed a fault. No need for a redesign, just fix the fault. Last time I had a puncture, I didn't modify my car to be a three-wheeler. Quote Link to comment Share on other sites More sharing options...
UglyDog Posted February 11, 2014 Share Posted February 11, 2014 [quote name='icastle' timestamp='1391612608' post='2359215'] 9/10 times I've seen this happening it's been either a faulty socket or forgetting to unplug the bass when not in use. [/quote] Yup, my money's on the socket. This happened to a bass of mine many moons ago, I couldn't work out why it was eating batteries within days until I tested the supposedly stereo jack socket and found the dead short between ring and sleeve... Quote Link to comment Share on other sites More sharing options...
Skol303 Posted February 18, 2014 Author Share Posted February 18, 2014 [b]UPDATE:[/b] I've just heard back from the folks at Fender about this repair, and it turns out that the problem is.... [i]drumroll please[/i]... a faulty jack socket! As suspected it's permanently switched on; hence the constant battery drain. I'm actually relieved it's not a fault with the pre-amp and all perfectly fixable. Thumbs up to Fender and the people at GuitarGuitar for handling this so well I'm very pleased with the service so far. Quote Link to comment Share on other sites More sharing options...
flyfisher Posted February 18, 2014 Share Posted February 18, 2014 Thanks for the update - it's frustrating when topics like this are left hanging. Should be a simple fix for them to replace the jack socket. Hopefully they'll also fit new batteries as well! Quote Link to comment Share on other sites More sharing options...
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