King Nothing Not Working

[ninjagrips]

First I would recommend checking continuity between Pad A and the input jack, as well as Pad F and the output jack, make sure those are what they're supposed to be.

I am getting continuity between these.

Any suggestions for what to try next?

 

[ninjagrips]

I still can’t figure out what’s wrong with this thing.

 

[vigilante398]

Since your voltages are okay I would probably recommend trying the circuit without the switch. Remove the input and output jack from the main PCB connections and try jumping input jack to pin B and output jack to pin E on the switch PCB.

 

[ninjagrips]

Thanks I’ll give this a try.

 

[Tassieviking]

Can you check the voltage between pin C (5) and pin D (6) on the switch PCB, C is the earth and D goes to the 1k resistor and then to the LED and then to VCC.
In bypassed you should have 9-12 volts, and then 0v when LED should be on.
You can also test the LED's current draw from C to D, when effect is not on you test the current between C and D with your meter. (the meter shorts C-D to measure the current and thus turns the LED on)

The only obvious thing I can see wrong is C5 looks to have a bad cold solder joint when seen from the component side, but I think it looks ok from the other side.

 

[ninjagrips]

So this is weird. I get 6.7V DC between pins C and D, and 6.2V DC at pads 5 and 6, when it’s on. When switched off, I still get 6.7V DC at the pins, but 0V DC at the pads.

When I switched the meter to mA, the LED lit up when testing pins C and D, and it read something like 6.1mA. This is with the switch both on and off.

When I’m testing mA on pads 5 and 6, I get 0, regardless of switch position. The LED just barely turns on in one position when testing the pads (I can see the faintest green glow from the LED), but comes on all the way when testing the pins.

This is all with no tube installed.

Could there be something wrong with the traces on the switch daughter board?

Edit: I still have yet to try jumping the input and output jacks to the pins. I’ve just been so frustrated with it that I set it aside for a while. Also had a hernia surgery, so I haven’t been playing lately, anyway.

 

[chris.knudson]

Your solder joints look good, but I can't tell on this one from the photo. You might want to check for continuity between those two pins.

 

[ninjagrips]

Just checked it. Not getting continuity between those two pins. Thanks for looking for me, though!

I think I reflowed all those joints since that pic was taken, also. The switch daughter board is definitely looking rough.

I also rebuilt most of the pedal at one point, just to make sure all the components were alright. Didn’t swap all the resistors, though.

 

[Tassieviking]

When I switched the meter to mA, the LED lit up when testing pins C and D, and it read something like 6.1mA. This is with the switch both on and off.

When I’m testing mA on pads 5 and 6, I get 0, regardless of switch position. The LED just barely turns on in one position when testing the pads (I can see the faintest green glow from the LED), but comes on all the way when testing the pins.

It would appear that you have a broken trace on the switch PCB in my opinion.
Pin "C" is connected to pad "5" by a trace on the PCB and pin "D" is connected by a trace to pad "6" on the PCB so there should be no difference when testing C-D or 5-6 with the meter set at mA.
The good news is you can easily check for resistance on C-5 and D-6, both should be 0 ohms or very close depending in how much resistance the meter picks up in the leads you are using.
If C-5 or D-6 shows high resistance then just put a small jumper between C-5 or D-6, whichever is the bad one. (lead from a resistor or diode will do for a small jumper)

Here is a mirrored picture of the switch PCB track side, it shows the tracks as they are under the PCB viewed from the top.
You can not see the trace from C to 5 because that is the earth and is connected to the other side of the PCB with small legs from the pads to the copper fill which covers the top of the PCB.
Second picture is the top of the PCB and if you look closely you can see the tiny tracks in a + pattern on pin C and pad 5.
Pin C has only 1 leg going to the flood fill ground plane, perhaps it should have had a trace from C-5 before the flood fill was made so the single leg was thicker.

 

[ninjagrips]

OMG thank you thank you thank you. I was pretty sure the problem was in that general area (switch daughter board), but I couldn’t pinpoint it. Thanks so much for your help.

I jumped pin C and pad 5.

Haven’t done a proper test, yet, but applying power and inserting a cable provided a promising result. LED came on!

Will report back after a proper test.

 

[ninjagrips]

Okay, so when it’s ON, it works!

When it’s OFF, it seems no signal passes through to the amp.

All I’ve tried so far is running it in front of an amp. Haven’t tried it as a preamp, yet.

 

[Tassieviking]

That seems very strange, the only thing I can think off is that you have a faulty switch.
When you have the pedal off can you put a small jumper from 1-2 on the switch, or just check with a meter if 1 connects to 2 on the switch with the pedal in the off position.
In the off position the input is going into A which is connected to 1 on the switch, the output is connected to F which goes to 2 on the switch.
In the off position 1 is connected to 2 on the switch so it should be a signal straight through the switch PCB, unless 1-2 is faulty in the switch.

 

[ninjagrips]

I’ll test that out and get back to you.

Thanks!

 

[ninjagrips]

So yes, I get continuity between 1 and 2 in the off position.

I’m getting continuity everywhere you mentioned.

But I’m still not getting signal when it’s switched off.

 

[Matopotato]

Did you manage to sort this out?
Fwiw, soldering 3PDTs with sligtly too long time (and heat) can make the lugs become loose in the plastic and the fuction is reduced or lost. Touch wood, but so far i have managed to reheat and push lugs back in when plastic is hot and soft.

 

[ninjagrips]

Nope, still in the same spot with it. Works when switched on, no signal passes through when switched off.

Thanks for replying, I’ve been hoping somebody had some other ideas.

I’m already on my second switch with this thing, but I suppose I could try one more. I feel like something’s wrong with the switch daughter board, though. I dunno.

 

[Matopotato]

Nope, still in the same spot with it. Works when switched on, no signal passes through when switched off.

Thanks for replying, I’ve been hoping somebody had some other ideas.

I’m already on my second switch with this thing, but I suppose I could try one more. I feel like something’s wrong with the switch daughter board, though. I dunno.

I haven't started soldering yet, so no experience from me on this build.
But, looking at the daughter board you can see the traces in the back, and work out which pad goes to which lug. Maybe you can use this info and bypass the daughter board with an unslodered 3pdt?

 

[Tassieviking]

I think this is how it is wired up

 

[music6000]

I think this is how it is wired up

Bypass is:
1 4 7
2 5 8
A - Input Jack
B - PCB IN
C - Ground
D - SW
E - PCB OUT
F - Output Jack

 

[ninjagrips]

Thanks y’all, I’ll give it a go without the daughter board.

Might be a few days before I can get around to it, but I’ll report back what I find.