# TC Nova Delay ND-1



## burger-patty-and-bacon (Aug 30, 2021)

I picked up a known non-working TC ND-1 Nova Delay.  It powers on but there is no sound.  Do we discuss t-shooting non PedalPCB stuff here?  Looking for some tips/pointers as to where to begin the t-shooting process to see if I can make this pedal work, else I will have to sell it for very cheap.


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## BuddytheReow (Aug 30, 2021)

We'd be more than happy to help! Share some pics of the pedal and a schematic otherwise we cannot help much. One of the first things to do is simply look at the board. Does everything appear to be soldered correctly? Use your DMM to test voltages at any opamp or transistor and post them here.

Use an audio probe and follow along with the schematic. Start at the input/output and work your way forward/backward.


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## burger-patty-and-bacon (Aug 30, 2021)

The first thing I did was google for schematic but they do not appear to exist.  TC seems to have never published them or just never made them available to public. 
I have the unit open and there are 2 PCB's.  One has the tap tempo/on off and LED readout, the second is the main PCB.  I looked over with fine tooth comb and do not see anything OBVIOUS.  The tiny little fusable link is good which makes sense becuase the unit does power on, it just does not output any sound and does not respond to the tap tempo button.  I'm afraid it's one of the SMD based components or the DSP or any such component like that which would be very hard to source.  Here are pics of top and bottom..


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## BuddytheReow (Aug 30, 2021)

Hmm. I would google the pinouts of all the ICs and the 7805 (the bent one on the left with the hole) and check all the power points. Power is usually my first place to check based on experience. I'm not that skilled in tracing a PCB to schematic yet so I'll have to defer to someone else.


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## music6000 (Aug 30, 2021)

burger-patty-and-bacon said:


> I picked up a known non-working TC ND-1 Nova Delay.  It powers on but there is no sound.  Do we discuss t-shooting non PedalPCB stuff here?  Looking for some tips/pointers as to where to begin the t-shooting process to see if I can make this pedal work, else I will have to sell it for very cheap.


TC Electronics are notororious for the dodgy Footswitch/ Soft Switch!
Give it a Good spray of Electrical Cleaner as it may be the culprit!


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## burger-patty-and-bacon (Aug 30, 2021)

I think the tap tempo footswitch button is just a secondary issue... the main issue is the zero output of sound. well, actually it makes sound IF i max out all of the knobs and make it do an endless delay feedback on itself but its super faint, quite as a mouse and barely audible.

googled the pin outs of the 7805CT. 






SO with power to the unit, check those 3 pings looking for .033uF    GND   .01uF?


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## Feral Feline (Aug 30, 2021)

Begin at the beginning.
Given you don't have a schematic, it makes most sense to me to start the audio trace at the input, rather than working your way back from the output.

I'd start with music6000's suggestion, then BuddytheReow's suggestions of taking an audio probe to it first, in conjunction with DMM set to continuity beep-mode and start roughing up your own schematic.

I got a ton of great help trouble-shooting an Electric Mistress here. I try my best to pay it forward, but alas I'm no EE and not very good at troubleshooting...


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## BuddytheReow (Aug 30, 2021)

For the record the output voltage of the 7805 should be 5v. That's what it's designed to do.


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## music6000 (Aug 30, 2021)

I


burger-patty-and-bacon said:


> I think the tap tempo footswitch button is just a secondary issue... the main issue is the zero output of sound. well, actually it makes sound IF i max out all of the knobs and make it do an endless delay feedback on itself but its super faint, quite as a mouse and barely audible.
> 
> googled the pin outs of the 7805CT.
> 
> ...


I was referring to the Soft switches in general, ON/ OFF & Tap Tempo.


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## burger-patty-and-bacon (Aug 30, 2021)

I measured 7805CT With DMM set to DC I get this:
PIN 3 5V
PIN 2 nada
PIN 3 10.8V

With my DMM set to "auto sense" I get this:
PIN 3 0
PIN 2 0
PIN 1 9 MEGA OHMS

I will have to build an audio probe. A nice member on the forum sent me a pdf guide on how to make one with
100nF (.1uF) Capacitor, preferably ceramic disc type, as it is likely to be small. 16-100V rating is fine.
• A few feet of stranded wire, preferably 2 colours such as red and black or red and green. Gauge is not
critical, but we'll say in the 18-24 gauge range is fine.
• A female 1/4 inch diameter Audio jack that is designed to be soldered onto the end of a wire; not the
type that mounts into an enclosure


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## BuddytheReow (Aug 30, 2021)

This is what it would look like. Drew it real quick with TinyCAD




The jack you use doesn't really matter as long as you can solder 2 wires to it: ground and the actual signal (marked tip). That goes to a capacitor. The capacitor should be roughly 100n and I used a box film one. It's purpose is to filter our all unwanted DC in the signal (you guitar sends AC signal). The other unused lead of the capacitor is your audio probe or you can solder a wire to that to make it a bit easier for testing.


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## burger-patty-and-bacon (Aug 30, 2021)

I have built my probe using a 100n box film cap.  I have the alligator clip on ground of circuit and my probe lead is hovering.  i have the INPUT of my probe coming from a guitar (for now) and then I have the output of the delay going to a crappy amp.  I strum gutiar and start placing probe onto the ND-1 trying to get output and so far guessing all the way along, zero output.

EDIT:  PROBE is working.  I touched the probe lead to the second lug down on the output jack (the black cable you see below is plugged into the LEFT MONO OUTPUT of the delay) and I can hear my strummed guitar coming thru my crappy amp.  This of course proves nothing other than the probe works since all I am doing is sending the output... to the output.


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## BuddytheReow (Aug 30, 2021)

IMO It may be easier to do it the other way around with the probe jack connected to your amp and your guitar going into the normal jack of the pedal. Test the input jack first with your probe to make sure that's not the culprit. If it is you've saved yourself potentially hours lol.

The pinouts of the various opamps will tell you where to put your probe. They're usually marked output.


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## burger-patty-and-bacon (Aug 30, 2021)

My probe was built with an Ibanez barrel jack, an alligator clip, a 100n BF cap and a random wire/clip lead I had.  The probe lead is not set to go as 1/4" output to an amp.

This is very interesting.  What I did was take a 1/4" to 1/4" stubby jack (like the ones to connect pedals).  I have that into INPUT LEFT.  When I strum my guitar and touch my probe to tip.  I GET PROCESSED SOUND!

If I touch my probe to the OUTPUT of the OPAMP 7805CT PIN 3 i do not get any sound.


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## burger-patty-and-bacon (Aug 30, 2021)

OK so here is some interesting stuff.  I have the PROBE clipped to ground and i have the probe female 1/4" output sending singal to my crappy amp.
I have a DRUM MACHINE plugged into input LEFT and when I touch my PROB to the output jack it sounds NORMAL.

when i touch my probe to the output of the OP AMP called 7805CT it is very faint and sounds like ass.  do i have a bad op amp and should I look for a 7805CT in the same physical layout and give it a go?  the voltages are good at the op amp.


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## BuddytheReow (Aug 30, 2021)

the 7805 is merely a voltage regulator to power a different IC correctly. No guitar signal goes through that. Your voltages for it above look good: Output (5v) Ground (0v as it should be) and Input (10v but can't confirm with out schematics). No need to test this further


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## burger-patty-and-bacon (Aug 30, 2021)

So what do you make of THIS.  Instead of strumming a guitar as my audio source (and wanting both hands free) I plugged in my old as hell Zoom drum machine and had a bass line going.  This worked great to test and get output.  I did not pay attention to what the output level was on the machine etc, but it worked fine and the delay pedal seemed to be normal.

I button the pedal back up, put the pedal on my board and into the FX loop..... back to no sound/barely freaking audible..  I pull it off the board, put it back on the bench, plug in drum machine.  works great.

What is this tell tale sign of?  Some kind of input resistor and the pedal only working if it sees a really hot line signal?

EDIT - Took it back apart, still using drum machine but turned volume way down on drum machine.  The issue is V E R Y low output.  When I probe the actual output jacks VERY VERY low output, however, when I put my probe on top of C135 or C134, nice big fat output.  I also see a few IC in this area, IC8 and IC15.  when I probe those, big fat output if i probe what I would call pin3 or pin8.  i so badly want to fix this but I do not know how.  crazy thought to wire C135 or C134 directly to the dang output jack.


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## BuddytheReow (Aug 30, 2021)

You're saying when you put a looper pedal/drum machine into the input the pedal works just fine, but regular guitar signal once you boxed it back up barely works? Forgive me for saying this, but is your guitar volume knob up all the way? No offense, but I've done this more that you think.

Try putting a booster before it if that does anything


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## burger-patty-and-bacon (Aug 30, 2021)

LOL!  Trust me, it is NOT the guitar pot.  It is EXTREMELY LOW OUTPUT from the delay pedal.  The only reason I was getting any sound at all with the drum machine is because the drum machine was CRANKED.  I am realizing now the OUTPUT level from the OUTPUT jack is about 95% less than it should be, regardless of drum machine or a bass or a very hot guitar, etc.  If I set the probe on top of C135 or C134 or on 2 of the pins of IC15 or IC8 it is very fat and fully wet signal volume and what should be coming from the output jacks.  So there is a break somewhere between input and output.  The question is, where is the break.  I cannot find a schematic so I randomly starting putting my test probe on everything and that is when I discovered very nice loud, processed output at those 2 caps and 2 IC's.

Can i jumper directly from those 2 capacitors to the outputs lugs?  I have to assume one is Left and one is Right.


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## Feral Feline (Aug 30, 2021)

Are C134/C135 close to the L/R output jacks?
What are the two large grey box caps next to the jacks connected to?

Using your DMM set to continuity-beep mode, put the DMM's negative probe on one side of C134 and using the DMM's hot probe, find every other component that's connected to C135 on that one side. Then do the same for the other side of C134.

Repeat the DMM continuity process for C135, both sides, making note of anything connected to it.


Couple things to point out:
1) Just because a cap has a high number doesn't mean it's near the output (and low number near the input such as C1 or C2) — schematic numbering goes however the person drew up the schematic wants, and if they started with the power section for numbering that's where you'll find C1, C2, etc.

2) Just because a component is located physically on one side of the board doesn't mean it's not connected electrically via a trace to the complete opposite side of the board. Keep that in mind while checking for continuity with your DMM.

So that said, jumpering from C134 and C135 direct to the output jacks may work, but may take a number of important stages of the circuit out of the equation, such as you get dry signal at the output, but maybe not the delayed signal or vice versa. Go ahead and temporarily jumper them, see what you get.

As I said, start at the BEGINNING, because as BuddytheReow said — doing so will save you potentially hours of trouble shooting. However, since you've now already established that you get signal as far as C134 and C135, continue from there — Be *systematic*, that's key.

Find what's connected to C135 and C135 and then audio probe those connected components. DMM-continuity check those newly-found connected components to see what they in turn are connected to — keep spreading out your web of connections, remember that just 'cause it's connected doesn't mean it's part of the audio path, so don't be duped into thinking you've found the disconnect at a point where the audio-path disappears. Keep checking continuity and audio-probing.


At least, that's how I would approach this.


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## burger-patty-and-bacon (Aug 30, 2021)

I picked up a known non-working TC ND-1 Nova Delay.  It powers on but there is no sound.  Do we discuss t-shooting non PedalPCB stuff here?  Looking for some tips/pointers as to where to begin the t-shooting process to see if I can make this pedal work, else I will have to sell it for very cheap.


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## burger-patty-and-bacon (Aug 30, 2021)

Yes they are very close to the outputs.  I marked them here in orange, the caps and the IC's I get full wet sound out of.  I guess I will keep probing and doing as you suggest but this is for sure needle in haystack!  Some parts of probing stop me dead in my tracks, others I keep getting audio as I go along.   I will try what you suggested.... somewhere in here the problem lies...  I am unsure what the two grey box film caps are connected to, I have only done audio probing thus far.


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## BuddytheReow (Aug 30, 2021)

Just remember that people get paid to do this tedious process. Be patient and take you time


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## music6000 (Aug 30, 2021)

Just for curiosity, have you checked for cracked/dry joints on the 4 jacks solder pads?
This is a common fault if someone has yanked a cable or stood on it.


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## burger-patty-and-bacon (Aug 30, 2021)

music6000 said:


> Just for curiosity, have you checked for cracked/dry joints on the 4 jacks solder pads


Yes I have looked over every milimeter of the board, both sides looking for any thing obvious like cracks or any such.  When i touch the top of C134 and C135 caps I get a glorious and very wet and loud and proper 700ms at 50% wet mix and it sounds NORMAL.  so, up to those caps things seem OK... its now trying to wtf the rest of it... this is not easy.


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## music6000 (Aug 30, 2021)

burger-patty-and-bacon said:


> Yes I have looked over every milimeter of the board, both sides looking for any thing obvious like cracks or any such.  When i touch the top of C134 and C135 caps I get a glorious and very wet and loud and proper 700ms at 50% wet mix and it sounds NORMAL.  so, up to those caps things seem OK... its now trying to wtf the rest of it... this is not easy.


Could it be the hidden gain setting?
I suggest checking the manual and adjusting the gain to your needs. (Press & hold the _manual_ button until 6 leds are lit.
Play at your maximum input level. Finished when nothing happens with the leds.


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## burger-patty-and-bacon (Aug 30, 2021)

music6000 said:


> Could it be the hidden gain setting?
> I suggest checking the manual and adjusting the gain to your needs. (Press & hold the _manual_ button until 6 leds are lit.
> Play at your maximum input level. Finished when nothing happens with the leds.


that is/was an excellent suggestion and recommendation but sadly that is not it.  the output is about 90 to 95% too low.  when i am probing and touch those 2 caps the output is proper.  when not probing and jsut using the output jack (etierh L or R and wehther input L or R) the volume is just so weak and meager.


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## burger-patty-and-bacon (Aug 30, 2021)

OK so holy sh*t.

I was deep, deep googling, desperate to find a schematic.  Using image search, all sorts of key words, whatever I could think of.  Some of the image hits started showing the PCB that I am now familiar with after staring at it for hours.  So, I came across a random post from 2012 which I am pasting below.  I was getting more and more excited as I read it because this is EXACTLY what mine is doing:

**********
"
Post by *Bernardduur* » 06 Apr 2012, 12:09

Just had one in that was not working.

With the PSU the unit powers up and just responds like it should, still, no output

The input was OK; on all lines perfect sound
On the output no sound; probed and checked with an scope and the signal dissapears just before the output jack

The outputs are wired up with an opamp that is buffering, put through a 1k resistor (SMD) and through a ferrite coil then fed into the output. The signal disappeared just after the 1k resistor. Flipped the board and discovered per output 2 transistors that, when activated, pulled the signal down to ground (guess for the panning delays). Q2 and Q4 turned out to be bad and grounded the output signal.

Only markings on the transistors: XL21; no idea what kind of transistors these are. All I could get from the units on the board is that they are NPN transistors, SOT23, with an Hfe of around 600.

Replaced Q2 and Q4 with new 2SC1815 (had no SMD laying around and the 1815 fit the SOT23 layout perfectly) and now the unit functions perfect again!"

***********

So, having truly exhausted everything I could think of, I said F it, let me find Q2 and Q4 and get at them.  They are MICRO TINY SMD chips using as the guy says SOT23 package.  I found them on the underside and was able to remove them using a hot iron, liquid flux and my copper braid.  These things are TINY!!!!!!!!!!!  Like an ant!  Once I removed them, guess what.  OUTPUT!  ACTUAL OUTPUT!  So I am heading to eBay now to buy a 20 pack of them for $1.99 with free ship and will do some micro SMD soldering to replace Q2 and Q4.  I have never dealt with components this small before.  Bless this dude for t-shooting and writing about it, cuz it helped me!  I will update thjis once my new ones come from eBay and I solder them in to see if the pedal goes back to normal working order.


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## Feral Feline (Aug 30, 2021)

What size of ant, though? The ones trying to steal my biscuits are about a millimetre long and 1/3 as wide, whereas the bloody fire-ant that bit my foot on a Malaysian beach was nearly a centimetre long ...

Ant-size kidding aside, glad you managed to dig up that info — Meneer Duur has provided many a good schematic to the DIY community.


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## PJS (Aug 31, 2021)

SOT23 is not bad for a first attempt at SMD soldering.  You will need magnification.  I say that as an older bloke, but my 12 year old with perfect eyesight also needs magnification .  I use a bench magnifier with a light.  You will need a fine tip on your iron. Put a blob of solder onto one of the pads on the board.  Use tweezers to put the component into the correct place and melt the solder blob.  Hold the component in place until the solder hardens again.  make sure it truly is in the right place - when it's held with one pad only it's easy to shift if need be.  Then once it is held in the right place it is easy to solder the other pads.  Just don't use too much solder.  Fine solder helps too.  I use .7mm.  Good luck


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## burger-patty-and-bacon (Aug 31, 2021)

Feral Feline said:


> Ant-size kidding aside, glad you managed to dig up that info — Meneer Duur has provided many a good schematic to the DIY community.


You mean you know the name of *Bernardduur* from 2012? 

PJS - Thanks for the tips.  I will be doing precisely all that!  I spoiled myself with a new X-Tronic iron when I started doing pedals and have a super fine tip that I use for PCB.  I also have a Radio Shack mag glass/light that I have had for about 30 years which still to this day works!  Amazing.

P.S.  These are the SMD NPN transistors I ordered on eBay for $1.88 with free shipping, you can't even get a pack of gum for that.  
I do assume these are going to be OK for the application in the Nova Delay?  The size is right, it is an NPN, I'm just not sure what the difference is between these MMBT2222A or the large amount of other "NPN SOT-23" transistors that are available.  MBT4401, etc.  I did not look at DATASHEETS but I would assume again the answer is in the datasheet?  This is all very new territory for me.









						20pcs ON Semiconductor MMBT2222A General Purpose NPN Transistor SOT-23  | eBay
					

The MMBT2222A is a general purpose NPN bipolar junction transistor. This item is sold in a lot of 20.



					www.ebay.com


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## Feral Feline (Sep 1, 2021)

burger-patty-and-bacon said:


> You mean you know the name of *Bernardduur* from 2012?


Ja, Ik weet his naam heel well — I've got a lot of his schematics on my computer. 
I don't know him personally or anything, and he's been doing this DIY thing a LOT longer than I have.


An aside: I believe Bernard's surname is "D'Uur" — the prefix "De" as in De Kuiper is shortened to the "D'" since a vowel follows it. A direct literal translation would be "The Hour".

Great, all this Dutch-talk and now I'm craving dubbelzout dropjes, or even better boerenkool met worst... Heel lekker!


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