SOLVED Pharmacist - No Bypass LED

[PangeaDestructor]

Haven't had an LED issue in a long time. Got my pharmacist all populated, tested it, soldered in the LEDs and while the boost side works normally, the bypass side doesn't light up. Treble and bass trimmers are wired up as normal pots. I've been poking around for continuity on the LED side, and things seem normal for the most part. Any help is much appreciated, cheers!

 

[carlinb17]

In the images you have, you don't have an LED soldered to the board. Is there one in it now?

 

[PangeaDestructor]

In the images you have, you don't have an LED soldered to the board. Is there one in it now?

Ha, yes there was one in there but I de-soldered it while trying to troubleshoot. Easier to get in there without it in the way. I usually test my leds in the holes loose before soldering, since they'll light up as long as they're making contact.

Edit to add - part of the reason I removed it was to make sure I didn't screw up the orientation, I've inserted a new bulb both ways into those pads and it does not light up.

 

[carlinb17]

ok good... the power for the led is pretty straight forward it's either R38 to LED to SW then ground or it's R100 to LED to SW then ground. I would check your foot switch on that side and see if you have continuity from the LED to the third pin from the right on the breakout board. Another idea is if you put your multimeter to Diode you can actually light up the led assuming you put the + on the anode and - on the cathode. either way its a good way to test the polarity of the led.

 

[PangeaDestructor]

Yep, that was my first step - always good to know I'm on the right track. I have continuity between the anode and r38, but none from the breakout/footswitch on that pin, on that side. I do have ground continuity with the footswitch ground pin.

 

[carlinb17]

cycle the switch and see if you get ground

 

[PangeaDestructor]

Yes, cycling the switch gives me a ground connection at that 3rd pin from the right.

 

[carlinb17]

Have you checked led to make sure it works? Also are you getting power to the anode side of the led?

 

[PangeaDestructor]

Tried multiple LEDs, no difference. The one I'm currently using to test lights up when tested with my DMM, and when pressed to the matching legs of the other LED.

Anode is reading 8.94v. Def a head-scratcher for me.

 

[carlinb17]

What if you jump the trace from the cathode to the r38 to see if it’s a bad trace then the same from r38 to the switch

 

[PangeaDestructor]

That did the trick, I think. Getting sporadic light when everything is making contact, turns off and on with the switch. Thanks so much for your help.

Really strange, what could be the cause there?

 

[carlinb17]

Bad traces do happen, not often but they do. It could also be a result of heat. Great job working through it!

 

[PangeaDestructor]

Just boxed it and fired it up, works great. Thanks again!

 

[PangeaDestructor]

Resurrecting this thread for a second, since it already has pics in case they're needed. Is this thing supposed to have kind of low output? It may be that I'm used to pedals hitting unity a little earlier, but the first 50% of the volume control seems fairly useless. It may be normal, since in the manual and all the demos I've seen, the volume is at or above noon, I'm mostly just curious. I checked all my values again and everything looks right to me.