Springboard foot switch issues - something’s broke somewhere…

[greysun]

Hi all!

Not really sure what's going on, but I cannot get my springboard to function - when I put my multimeter to the footswitch, I'm only getting 2v throughout the entire thing after the 5817. I already replaced the diode, used a 2nd VFE chip I had from another project, replaced the tq2-5lv, swapped another switch in, and it just turns on the LED and nothing else. Certainly not getting strong readings at the 5v regulator even though it is heating up.

I've traced all my leads, ensured the parts are all correct, triple checked that there not a ground short somewhere... It's gotta be a bad part in there somewhere, I just don't where or how to find it.

But honestly, I don't love these footswitch systems - there's a lag on my distortion 3's that's JUST enough for me to notice and trip me up, and it goes haywire if I accidentally trigger tap it (easier to do on the momentary switch than a standard 3pdt).

If I wanted to just make this a normal 3pdt footswitch, could I simply just make a daughter board with some power filtering and wire it up normal? I'm not sure how the whole split rail thing works with this board, so hopefully someone can tell me what to do here...

(also, could by my leaf sockets are just weak, but they are not holding this brick in very well - are some stronger than others, or is this thing just a beast to cram into em?).

[greysun]

I had asked something similar before, re: using a normal foot switch, but given this is a split rail situation, just trying to make sense of it all and what filtering is needed.

[greysun]

Some further testing and a bit of copilot help later:

into D1: 9.3v
out d1: 9v
D2: 2.5v
Inductor In: 9v
Inductor Out: 2.5v
resistance across inductor: 24ohm (this is the same in my Distortion3 projects, which work)
C1+: 2.5v
78L05 I: 2.5v
78L05 O: 0v
BS170 D: 8.6v (ish)

During the process, I replaced C1 entirely and swapped the 7662 chip. No luck.

Copilot seems to think it's either a bad D2 (16v zener, which I've already replaced once) or the regulator (78L05, which, of course, I'm out of now). Maybe micro center will have some...

Any other advice here is appreciated. Thanks all!

[greysun]

Update: Since I had other VFE switch boards, I just built a new one.

Once I removed the 78L05, the resistance from its output pad to ground was 0, which meant something was shorting to ground somewhere, but I could not (and still cannot) find where it was. Part of me wonders if it was a rogue strand of wire with one of my connector wires to the PCB, but we'll see later when I have more time to test the non-working board again now that I've stripped those off of it.

This meant that the 78L05 was fine (as proven by its use on the now-working new board), as were all of the components and IC chips.

*sigh* - it's messier in there than I like, but I'll still do a build report, if for no other reason the learnings, lol. This one nearly broke me - I've had to troubleshoot before, but never just rebuild it completely. Luckily it works, so I live to tell the story...

An aside: I actually think the switching system is brilliant; similar to something I was trying to build an effects loop program using an Arduino with some transistors, zeners and an optical muting system to power the relays with a bunch of programmed banks for memory - I got it fully working on the breadboard, but getting all of it mounted in the enclosure with the neopixels and LED screen was a bit much (I bit off more than I could chew there - maybe one day I'll finish it). But on a per-pedal basis, I guess I'm just old school - forgive any implied judgment, "get off my lawn!", etc.

Enjoy the weekend, folks!