Aion Helios RAT - No Signal (basically)

[pervyinthepark123]

Hey, I'm working on a Aion Helios PCB RAT clone, have it basically worked out, a few minor substitutions but my problem is before any such.
So, I've been testing it with the output grounded but not connected, no 3PDT switch yet, just checking signal flow.
However, my signal cuts after R2/C2, before the LM308, which has similar voltages to here.

Testing it with the grounded output jack, I did however somehow get a tone just super briefly a couple of times from C3, just long enough to tell it was a definite distorted guitar tone of some kind.

I've since resoldered probably every joint at least once and checked all offboard components with multimeter for continuity. Any suggestions where to look?

[pervyinthepark123]

UPDATE:

Since yesterday, I've resoldered every joint, some multiple times, been testing with an audioprobe and multimeter, checked every single connection via multimeter and they all looked good.
My voltages, upon reaffirming myself of pinout and checking again with multimeter I found its a little off:

Using a 9.6V Line 6 power supply.
1: 0
2: 4
3: <4 (keeps draining??)
4: 6.73
5: 7.96
6: 8.93
7: <2.3 draining
8: 0.15

Pics here
http://imgur.com/a/vTswO

[Kipper4]

Is that Line6 power supply AC or DC?

[duck_arse]

something is very wrong with your voltages, or your measurings, or your pin numberings. pin 4 should be 0V, ground, earth, no voltage. it should basically be a sort circuit with your jack sleeves and the (-) supply. and, pin 7 should be at the (+) supply voltage (less a little across R9). not to be rude, but how advanced in measures/meter usage are you?

also, that cap in the bottom right corner, the 2 electros - the value is not so critical that you can't put A SINGLE 47uF cap, if you don't have a 100uF. it might also save you some grief with shorting leads.

.... I've been testing it with the output grounded but not connected ....

what does this mean? where are you testing - I see you don't have the fet fitted?

[pervyinthepark123]

Its definitely 9.6VDC, US standard and 200mA.

This is my first IC build, I've built a couple fuzzboxes before and have been working on a few things since then, mostly a big muff and now this and a Klon because I need to wait for china shipping on the muff.

So apparently I did mix up my pinout... I posted the last and took voltages in a rush so I could join my friend jamming in the other room...

1: 6.74
2: <4 (draining)
3: 4.02
4: 0
5: 0.18
6: 3.3 (drains)
7: 8.9
8: 7.9

Thanks for letting me know that cap isn't very critical, I'm aware its sketchy and once I get it working I would shorten those leads and tape it to prevent shorting. I may switch that out. I did check it and that cap is totally connected with continuity.

What I mean by testing with the output grounded but disconnected is that I unconnected the tip from the output of the pedal, but kept the shield grounded, and followed the input to the chip with it.

And yeah, no FET fitted yet, I don't have any FETS. I might try different trannies I have on hand since its just used for volume. I haven't been testing the final output yet as I know my problem is much before the FET.

[pervyinthepark123]

Any idea why my voltage would constantly be drained as and after I read it? It seems to reset back to around 4-5.

Sorry I don't know too much, I'm relatively new to this and am teaching myself
Documentation: https://www.dropbox.com/s/g7j17h929ro49gj/aion-helios-rat-documentation-v2.pdf?dl=1

[duck_arse]

draining - no. no idea why. what type of multimeter are you using? we need mor voltage measures - power off, pull the IC out of the socket, power on and again measure the voltages at the IC pins.

and, we want the voltage at the junction of R10//R11//C13. then the voltage at the R1//R2 junction. your empty socket should read only at pins 7, 4 and 3.

if you plan on not using a fet, you'll need to be somewhat creative to get its replacement to work.

[pervyinthepark123]

I suppose I'll come to the FET thing when I come to it...

My multimeter is a HoldPeak HP-90C

With no IC the voltages are:

2: 0.03 (interference?)
3: 4.36
4: 0
6: 0.03 (same?)
7: 9.7

C12: 9.7
R10: 9.7/4.8
R11: 4.8/0

So, 4 SHOULD get a reading with no IC, despite going directly to ground you say? Um what can I do other then this single solder joint then as it goes to nothing?

I also noticed C3 only gets a reading with the op amp in, but thats probably typical in this circuit since its looped in the LM308.

[Fndr8875]

feel your pain buddy i ordered a halo - big muff from aion over thanksgiving weekend. Im getting way off voltages on q1-q4.  And im having the same prob you are no signal , this is only my 3rd  pcb ive bought but for me my prob is i always , no matter what medium im using end up with to much solder flowing, no matter how hard i try to get those tiny perfect joints i see with minute amounts of solder. If you keep hitting board with heat and more solder the mask will at least i think from the looks of my last try on a guitarpcb board bulge up from excess solder which  can effect other traces since they are so small and close together, at lease i think i dont know this is fact but it looked like the pad had taken as much solder as it could and from apply way to heat over and over again that the excess solder had started to run down trace. My big muff build ive got done building few days ago doesnt look like this at all as my soldering has gotten a little better , i havent had the time to properly go through and do all the troubleshooting steps, other than voltages on trannys and so thats where im at. Its frustrating as hell spending so much time sourcing parks, carefully building and then getting no signal. only othe thing i can suggest is double check you have the correct resistor values. The big muff has 20 something resistors so its gonna be  more of a bitch  for me i think, pls keep us updated bc i would ilke to build a ratt soon, i have one i etched and built from tonepad, but it just doesnt look like it will be very durable in the long run. thanks and good luck to you

[pervyinthepark123]

Yeah, I have a Big Muff PCB from Aion and have been having problems with it as well.
My Fuzz Factory  went so smoothly... very simple circuit though.
I wonder if maybe Aions interior traces are too close together and can't handle the heat. I see permanent sweats as soon as I start soldering on all his boards. Probably not, I just can't believe the amount of trouble I've had with it, so I ordered some custom PCBs since my intention is to load mine with mods anyway.

[duck_arse]

sorry, I should have pointed out, 0V is a valid voltage. if we want ground and don't get 0V, we know we have a problem. so your voltages are good, poke the IC back in, do your measures again, and we'll think on it from there.

pin2 connects to pin6 via a resistor, so we expect much the same reading at either pin. if they were different, we'd have a lead on the problem. those two pins are isolated from DC by capacitor connections, so if there were any DC voltage without the IC, we would again have a lead. so we are at least able to say a few places where the problem isn't.

[pervyinthepark123]

Okay thank you so much! Seems ICs are a little more complex then transistors (hah)...

Voltages, IC in:
1: 6.74
2: 1.44
3: 4.03
4: 0
5: 0.22
6: 1.48
7: 8.98
8: 8.01


IC out
1: 0
2: 3-4v? (Last time I checked this had 0.03v! What?? I havent even changed anything!!
3: 4.36
4: 0
5: 2-3v?? from 0?
6: 2-3v? (same?)
7: 9.7
8: 0


C12: 9.7    R10: 9.7/4.8       R11: 4.8/0

So I got normal readings with IC in but with it out, everythings whacky... I havent changed anything but values have since I last took the IC out... a lot...

I feel like either my PCB or chip are broken.

[duck_arse]

nearly, but nope, your readings are bad with the IC in. and now also bad with it out! pin6 voltage is following pin2, but should be similar to the bias voltage at pin 3. I don't know why your voltages are changing, unless your solders are worse than they look (hope that's not too blunt).

I can't figure it out - possibly a bad socket? now fritzed opamp? something moving? do you have another opamp you can try (an LM741 should work)?

out of interest, what value resistor do you have fitted for "LEDR", 4R7? it should be not less than 4k7 (yllw-vio-blk-red-brn).

[tl-ww-ext]

Just finished this build, got it working & it sounds really good. At first I had some really strange voltages until I realized I had put in the 1N4002 (D5 I think) ass-backwards. Fixed that & everything was fine.

I'm just wondering about that C11...  It should be 100 uf and it looks like you have 2 47 uf caps in series.  With caps, doesn't that reduce the capacitance?  I.e. it looks like you now have 23.5 uf where 100 uf should be.  I don't know if that's the problem, just worth looking at.

T

[pervyinthepark123]

I don't have any spare ICs that'll fit.... the LEDR was indeed a 4R7, which I swapped now and am swapping the caps, taking a meal break atm... Forgot my noodles on the stove working on this lol..

@TL, the caps on C11 were actually 220... I had plenty of 180s but only low voltage 100s at hand. My diode is also facing the right way

I'm recheck my solders after I finish replacing C11 with a single cap per ducks original suggestion.

I'll also double check that I put in 1n4002 and not 1n4007, will update.

Although, if the switch isn't hooked up and I'm just testing it with ins/outs/p/g, and with no LED, should LEDR even matter?

UPDATE: So the protection diode is a 1n4007 and not 1n4002... apparently my bag is mislabeled and I do not have those. Should work though? New Rats use 1n4007s from what I've read.
Current voltages:
Voltages, IC in:
1: 6.74
2: 0.42
3: 4.03
4: 0
5: 0.27
6: 0.6
7: 8.98
8: 7.96


IC out
1: 0
2: 0.66
3: 4.32
4: 0
5: 0
6: 0.66
7: 9.68
8: 0

Just got the distortion sound on C3 back... not exactly where it belongs lol. Back to testing.

[duck_arse]

diodes - the 1N4007 is rated for 1000V. the 1N4002 is rated for 200V. they are both rated at 1A. as they are wired reverse-shunt to protect the pcb, their voltage rating DOESN'T MATTER. unless you are connecting 300V as the supply, don't change what is fitted. the idea of that diode is to short the external power supply when reverse connected - for a short time only. if you don't notice, either the diode draws all the supply current until the plug pack expires, or the diode loses the fight with a higher current supply, smokes, and leave the rest ot the circuit to the mercy of the (backwards wired, probably very angry) supply. goodbye semiconductors, hello smoke.

caps - if you have 180uF at 16V (or 25V or 35V or 50V) electros, use them for the 220uF. or for the 100uF. it really doesn't matter the value, +/-75% will do for the supply bypassing. just don't be messing with paralleling and seriesing, it's not worth the hassles.

audio probing - pin 1 and  pin 8 are of no real interest to us. distortion/no distortion - it's of no use to you unless it is appearing at pin6. pin 2 is also a no signal point, we just do DC voltages at pins 2 and 3 usually (virtual earths and all that), and when working, pin 6 (voltage) will follow pin 2.

your IC out pin 2 and 6 indicates a problem of voltage where it shouldn't be. so, IC out, power off, meter to resistance. go around the socket and measure the resistance-to-ground for each pin, then try resistance-to-the C11//R9//R10 point.

after that, I'm about at a loss, we need more ideas. I'd be starting to disconnect parts like R3 and the distortion pot (solder tack a resistor across, any value 10k~100k) and C7. oh, and the led resistor, at 4R7, is about useless, the led would be blinding, possibly burning out.

[aion]

I've only ever had one case where there was a verified PCB manufacturing error (one individual board for one person, I mean - not a batch of boards) in five years, so chances are very low of that being the issue.

I'm gonna take it a step back... please take this as constructive criticism, and know that it comes from someone who started building pedals seven years ago, and for the first year, not one of them worked out of a dozen that I built. And they were bizarre issues, never the same thing twice, and impossible to troubleshoot. I had to pitch all of them. It turned out to be a rather serious issue with my soldering technique. Once I worked that out, from that point on, I've never had to scrap a build - but it took a very, very long time to reach that conclusion, and on several occasions I almost quit entirely.

Knowing that several pads came detached on the Big Muff, and having seen the Rat PCB, you've got some work to do on your soldering technique. You are either running the iron too hot (it should be around 650-700 degrees), using the wrong kind of solder (definitely don't use lead-free when just starting off; 63/37 is great, or 60/40 if you can't find it), using too broad of a tip (you want a narrow pencil-tip conical one, not a chisel tip), spending too long with the iron on the pad (a good joint is made in only 1 to 1.5 seconds), or a combination of the above.

When you get to the point where pads and traces are coming detached and you're re-routing components to nearby pads, it goes from a situation that can be troubleshooted (troubleshot?) with enough information, to a situation where the problem could be anything or nothing - where voltage measurements might get you someplace or might be a red herring for the real problem (since proper voltage doesn't equal proper functioning).

You're going to learn a lot from the process of troubleshooting the issue, but it may be that this one just can't be fixed - that this one should be scrapped as a learning experience and you'll knock the next one out of the park.

[pervyinthepark123]

Theres no pads broken off the RAT. My solder iron is single heat, which might be my problem if my solder joints ARE bad, and the tip is a little bit worn and sometimes I have to tin it often. My joints don't look bad to me though? Most boards I see pictures of are totally goopy everywhere and oversoldered. If you mean the differing shades of the solder, I did use two types of solder and the one always looked "cold" comparatively to the other no matter how I did it. The pads broke off my Big Muff trying to remove components, I need to get solder braid or something because I don't have much of a good way of dealing with excess solder in a hole I'm trying to fill.

Last night did more testing before bed and found that C4 was shorted! I hope thats it will update after I get my shit figured out

edit: uhg... sorry I am so rookie this is embarrassing. I'm so glad for this community being amazingly helpful, and for Aion trying to help me, but it seems my C12 cap is accidentally polar tantalum, I thought it was a really big ceramic cap... uhg... too many chinese parts for this novice..

edit2: I think when I get my soldering braid in the mail I'm just going to undo nearly everything and start from scratch...

[duck_arse]

I've been looking at your pics most of this week, pervy, and have only just noticed that your board doesn't match the one in the V2 docs. what's that all about?

if that big green lump is in C12, it is a greencap, from where I'm sitting, and NOT polarised.

if your C4 cap is shorted, cut it out, throw it away. but how come your pot read varying resistance? mystery upon mystery ......

[aion]

There was a very slight tweak to the layout about a year ago and I only recently realized I forgot to update the docs! Doesn't affect the parts list at all though. I need to get the photo updated as well.