| Author | Message | ||
| emjay
Junior Username: emjay Post Number: 47 Registered: 3-2005 |
Hello all, I have a '96 Essence 5 with side LEDs that I bought from a seller on Ebay a couple of years ago. As far as I can tell, it is in original condition. There was an early problem with intermittent LED flickering, that I dealt with by shaking the bass until they stayed on. That problem slowly got worse until they recently went out altogether. I checked the wiring connections to the switch and to the batteries (they all seem OK), and put fresh batteries in. LEDs are dead. I also have a MK Sig Deluxe with a minor glitch that just requires the switch to be toggled a few times to get the lights on. No big problem. I don't really used the LEDs that often, so does that factor into any known issues? Any suggestions on how to get this fixed, aside from shipping it back to the factory? I don't have any electronics testing gear. Would the Amp Shop and Music Parlor near where I live in West Palm Beach FL be qualified to repair Alembics, if I need to go to a pro to fix it? TIA, Jeff | ||
| davehouck
Moderator Username: davehouck Post Number: 7916 Registered: 5-2002 |
Jeff, if Mica hasn't responded to this thread within a few days, you may want to give her a call. Remove the truss rod cover; I think you should be able to reach the LED leads there. Try moving them around some and see if they come back on. Borrow a multimeter (or purchase one, they're good to have around for a variety of reasons). Sit to check resistance (ohms) and place the probes where the two wires from LEDs connect to the switch. If the circuit is good, it should show some resistance; if the circuit is broken, it should show infinite resistance. You can also use the multimeter to check DC volts at the switch for the leads coming from the batteries. These tests should determine if the problem is in the leads going from the switch to the LEDs, or the leads going to the batteries, or the switch itself. | ||
| davehouck
Moderator Username: davehouck Post Number: 7917 Registered: 5-2002 |
As for the MK, yes, the switch may be "dirty" from lack of use. Toggle it back and forth a couple dozen times and see if starts working consistently. | ||
| emjay
Junior Username: emjay Post Number: 48 Registered: 3-2005 |
Thanks for your answer Dave. I'll try the simple suggestion first. If that doesn't do the trick, I guess I'll just have to finally bite the bullet and get a multimeter sometime soon. Even though this is premature to ask at this point, I was just thinking that if the problem is with the LED leg of the circuit, is that complicated to fix? I read in an archived LED problem thread that one issue required the fingerboard to be removed to repair the LED strip itself. Would the local AS&MP I mentioned be a good bet to do the repair, and would they need a wiring diagram to do it? Alternatively should I ship it back to Alembic, or maybe to Bass Central (which is at least in FL), if the repair requires experience with Alembics in particular? | ||
| davehouck
Moderator Username: davehouck Post Number: 7919 Registered: 5-2002 |
I think the simple answer is, if it's in the LED circuit, then yes the fix is not simple. But that question is for Mica. | ||
| dfung60
Advanced Member Username: dfung60 Post Number: 380 Registered: 5-2002 |
Just a small nit. LED stands for "light-emitting diode". Diodes allow electrical current to flow in one direction and block current flow in the other direction. When current flows across the internal junction of an LED, it emits light. This is different than a regular light bulb which doesn't have a sense of polarity. Diodes also have a critical current level that you must exceed for current to flow. So, if you want to test the LED side of the circuit, it's not going to be quite as easy as testing for continuity with a multimeter. You have to connect the test probes in the correct polarity and you have to exceed the current threshold as well. It's unlikely that you'll do that with the small amount of current provided by the multimeter. The way that you need to test the LED string is to connect it to a known good power supply that can provide suitable voltage and current. You can do a regular continuity test for the rest of the switches and wiring harness. If the problem is in the LED strip on the side of the neck, it's going to be a really big deal to repair, and not something that anybody will want to do outside the factory. The way that the LEDs are placed in the neck is that a slot is routed along the entire side of the neck from headstock to neck joint. A thin filler strip is produced to fit in the gap and LEDs and LED wiring is installed on that strip, then inserted into the side slot. If an LED or the wiring has failed in the strip, then I think they will have to reroute the slot and replace the strip. As you can imagine, this is a very delicate, complicated, and probably expensive process. I don't think that you can remove the existing strip in any non-destructive way. I had one of the rare graphite-necked Series II basses built back in the 80's. It was originally constructed with insufficient neck relief and tended toward having a very buzzy action (I play with more relief than most, I think). As was the regular practice with Modulus-constructed necks from that era, there is no truss rod. After many years, I decided to address this problem to make it right. I have a lot of Modulus instruments and was friends with Rich Hoeg, who was the Modulus "custom shop" builder and master setup guy for many years. He took a look at the instrument and told me that he might be able to correct the problem by grinding the necessary relief into the existing fret tops, but that he was unwilling to pull frets or plane the fingerboard for fear of upsetting the LED strip at the side of the neck. I suspect that this is a oonsideration for any LED Alembic, not just the graphite ones. David Fung | ||
| davehouck
Moderator Username: davehouck Post Number: 7937 Registered: 5-2002 |
Thanks David !!! | ||
| emjay
Junior Username: emjay Post Number: 49 Registered: 3-2005 |
Turns out that the problem was in one of the four battery connectors. One of the terminals was loose, and finally came off the hard white plate with the battery when I removed it. In my experience, some of these hard plastic connectors don't fit the batteries that easily, causing strain on the soldered terminals. Does Alembic prefer these for a particular reason, or can the more common soft plastic connectors be installed instead, in the future? Maybe they will provide enough "give", so that the terminals would not be strained - and eventually break off. In any case, I'm really glad that it doesn't appear to be a more serious issue. Thanks for responding! | ||
| artswork99
Senior Member Username: artswork99 Post Number: 651 Registered: 7-2007 |
Glad to hear it was only the battery clip! | ||
| davehouck
Moderator Username: davehouck Post Number: 8003 Registered: 5-2002 |
Great news! |
