Diagram for Zendrive included.

[287m]

serendipity madbean?

[Zenbend]

The Readings I had taken from the board pins from the solder side 1 2 3 4 anti clockwise from bottom to pin 5 up to 6 7 8
Tried two different ground wiring as it always first for my builds.
checking  all grounds when connected on and off board.
But idea was to minimize wiring and weak points, I tried off board star ground as a reasonable solution,so tried off board grounding with stars points off the board (jacks and 3pdp) to the input jack and back to the board Nearest the input jack (similar to a star configuration in a guitar running back to the copper tape in the back of the controls).
Wanted to rule out the boards many ground points possibly were a weakness and were causing loss of signal. Although that was not the case.

had explained earlier when the switch is in bypass mode there is clear signal passing to the amplifier from my signal, with some reaction from volume knob and treble knob.

<UPDATE> I no longer get any guitar signal when switched on (only in bypass(Terrible sound as if there is high current on the input) here's a schematic.

[bluebunny]

The Readings I had taken from the board pins from the solder side 1 2 3 4 anti clockwise from bottom to pin 5 up to 6 7 8

Rob's picture (and any other you might find) was from above: i.e. the component side, not the solder side.

Edit: like this:

[duck_arse]

serendipity madbean?

board doesn't match any the madbeans I looked at [and OP won't tell].

BUT - in this pic, and considering we are working with no layout ......


in the bottom right corner is a 2k2 resistor. I see no such on the circuit dia, only a 2M2 [red red green gold - or - red red black yellow brown]. if you have 2k2 at the input pull-down position, no signal worth speaking of will pass that point. also, please confirm that your 1k5 replacements for the 1k's are - brown green red gold - and NOT brown green orange gold.

and can i again ask - origin of the board? help us help you.

[Zenbend]

Yes I understand,  readings being in the correct side would help. 😂 this is the website which was attached to the order  ���������������������������������������������������Www.Efecty-diy.pl

Pin 1 -5.5 pin 8 - 10.8
Pin 2 - 5.9 pin 7 -6.6
Pin 3 - 4.4 pin 6 - 6.7
Pin 4 - 0.   Pin 5 -5.6

Also have changed inputs  2.2 k resistor to a 1 Meg. that's all I've got in stock. The 1.5 is red green brown! Cheers

[Marcos - Munky]

So, let's point a few things:

Www.Efecty-diy.pl

Link doesn't work. Post the correct link.

Also have changed inputs  2.2 k resistor to a 1 Meg.

2k2 = 2 200 ohm. 1M = 1 000 000 ohm. See the difference? But in the schematic you've linked, it's a 2M2, not 2K2, at the input to ground. So you can use a 1M.

The 1.5 is red green brown!

Red green brown is 250 ohm. Do you mean brown green red (and a 4th band)? That does make 1K5. But I'd check one of these resistors using a multimeter to be sure - not on the circuit board, it have to be pulled off.

Personally, I'd buy the correct 1/4W resistors.

[Zenbend]

http://efekty-diy.pl/zendrive.html

Accidentally placed a carbon comp 2.2k  will learn for the next time. Thanks !

That's right it's with four bands. brown, green, red with a fourth (gold)

[Zenbend]

I've been having delays with Shipping during the holiday season. Should be getting some 1/4 watt 10k Carbon film resistors as well.  alas 100p capacitor made of dipped construction located by the input - to ground.

[Rob Strand]

Pin 1 -5.5 pin 8 - 10.8
Pin 2 - 5.9 pin 7 -6.6
Pin 3 - 4.4 pin 6 - 6.7
Pin 4 - 0.   Pin 5 -5.6

As far as your problem goes I wouldn't worry too much about the part values.

Your DC voltages are sort of OK but they still look like something is wrong.

With pin 8 at 10.8V I would expect pins 1, 2, 5, 6, 7 all to be quite close to 5.4V.
Pin 3 might be a little bit lower because the meter loads down the circuit. 
The exact voltage would depend on your meter.  Most meters would be 5.2V and some meters could be as low as 1.72V.

Some other things you can do:
1) Measure the voltage on the 47uF cap.   We expect about 5.4V
2) Measure the voltage *across* the 470k resistor.  We expect close to zero.
3) This re-checks the DC voltages with input shorted just in case you have oscillation.
- Set the footswitch to EFFECT (not bypass)
- Short the input to the pedal (or the input to the board) to ground
- Check the voltage on pin 1 and pin 7 and see they have changed from the previous measurements.
4) Last resort.   Remove the IC from the socket.  and measure
   DC voltage on each of the socket pins.   
   We expect:
   pin 8: 10.8V
   pin 3: between 1.7V and 5.2V
   pin 4 solid 0V
   other pins should be zero but they might flicker.

If all those check out OK I'd start thinking maybe there's something wrong with the opamp.

[duck_arse]

I've been having delays with Shipping during the holiday season. Should be getting some 1/4 watt 10k Carbon film resistors as well.  alas 100p capacitor made of dipped construction located by the input - to ground.

I don't want to sound like an arse, but, can you tell us the markings on the cap you have fitted at C2 please? and thanks for the site link.

[Zenbend]

It's a .1uf which is in C2
Just checked that decimal Nf- Uf conversion.
This should be a .0001uf 

[duck_arse]

no. sorry, yes, 0u0001. caps aren't marked that way in the real world, tho. many many many years ago it might have shown mmF, or uuF [apologies to antonis].

100pF = 0n1 = 0u0001

pF = 10^-12, nF = 10^-9, uF = 10^-6

your cap should be marked 100p OR 101 OR 0n1 - only sometimes "100" without multiplier.

the 100nF will eat all your gain in the feedback loop. as noted above, this probably won't fix the DC problems ......

[Zenbend]

Ok that makes sense. So maybe the voltages are ok or close.
I sure feel thankful with the build getting so much attention 

I have the first few readings.

R2 - 9.9VaC

C2 - 3.5VaC

Pin 1 - 13VaC

Pin7 - 15VaC

[Marcos - Munky]

So, did you corrected C2 value?

[duck_arse]

please confirm what type and voltage power supply you are using. you should not be measuring AC voltages, anywhere on the board. what is the DC voltage on the IC pin 8?

[Zenbend]

Yes, DC is correct still figuring out how to use the Ohmmeter,
the readings were actually using no capacitor will update one i get one.
I only have a ceramic capacitor (0.0045)..  there were such strong winds couldn't make a trip to the store.
So might be better to wait and buy a few, ((.0001)) or ((100p)) capacitors tomorrow?

[Marcos - Munky]

You need a 100pF cap and you want to use a 4500pF cap. Just get the right cap, it's a cheap one.

[Zenbend]

Replaced C2 with a 101pf 
These first two are readings  (open circuit)
1 and 7 were taken with shorting jack open with a wire running to a ground point on power supply

Pin 8 was measured with out the shorting wire to the power supply ground point.
measuring with shorting wire it is (O VDC) Zero
Hope this helped.

R2 - 2.7VDC (across)

C2 - 7.8VDC

Pin 1 - 6.7VDC

Pin 7 - 2.7VDC  (seems low?)

Pin 8 - 11.2

[Zenbend]

Ps, I'm still not sure about the voltage loading on this meter being different each time I do a reading thanks for the tip about the loading of different meters. Hope I can still get some headway's here  by the end of the Weekend.

[Zenbend]

 :icon_wink:Update! Just checked the pins with the Ic removed.
Looks like everything is pretty solid 0! Expect maybe 200Mv on pin 3
Pin 8 has the full power supply voltage. 15VDC today
Also I tried a new Ic and it was similar so must be a wiring error or short circuit somewhere. I hope these new details might help.