Need help troubleshooting HM2 kit gone bad

[duck_arse]

120R and 10k resistors - plz check them all with your meter on ohms, power off. and does that resistor really have a band with a zero inked on it?

[amaurythewarrior]

Well I'm back with a new battery at last!
It sounds apparently ok, no high shrieking, although technically the battery reads 8v and was supposed to be expired 08/2018
I still have to try it with guitar, in the example it's line level music from youtube through my interface.. . but controls seem to behave normally, although I'm not entirely sure about volume and dist. What do you guys think? It's definitely not supposed to be a nice distorsion, I think even hear I can hear it's famous "chainsaw" sound.
https://soundcloud.com/amaurythewarrior/hm2battery

EDIT: here is with guitar
https://soundcloud.com/amaurythewarrior/hm2batteryguitar

prrrrrobably not what it should sound like. i'll try to take more measurements now

[amaurythewarrior]

new readings:
IC1
1:3.5
2:3.5
3:0.5
4:0
5:2.5
6:2.5
7:2.5
8:7
IC2
1:3.5
2:3.5
3:0.5
4:0
5:0.5
6:3.5
7:3.5
8:7
IC3
1:3.5
2:3.5
3:3
4:0
5:0.5
6:3.5
7:3.5
8:7

T1
e:4
c:0
b:7


T2
e:0
c:3.5
b:0

T3
e:6
c:2.5
b:5

C20:2.5
c19:7

pulling my hair just a bit

[amaurythewarrior]

120R and 10k resistors - plz check them all with your meter on ohms, power off. and does that resistor really have a band with a zero inked on it?

thank you, will do.
And yes, it does, 0 or just a circle. didn't see it until you pointed it out. can barely see it with the naked eye.

[antonis]

Your measurements make no sense..
(neither for Vbias nor for transistors..)

I believe it's more a buid issue than AC supply damage..

[amaurythewarrior]

Your measurements make no sense..
(neither for Vbias nor for transistors..)

I believe it's more a buid issue than AC supply damage..

I'm more worried I might no be making the measurements correctly
I measured the 10K resistors,
R3 is k5
r11 2.5K
R31 6K
R32 6K

Is it even possible? Should I just take the whole thing apart and start over?

[antonis]

Just a last attempt before taking it apart..

Your build seems clear enough so try to isolate pots back from PCB via any non-conductive thin material..

[amaurythewarrior]

Done already, that was part of what they provided.
So, before taking everything apart I guess I'll check the value of every component, I think I've already did that, but maybe I wasn't thorough enough.

[amaurythewarrior]

I've checked all resistors with my multimeter, however, for some of them I got really weird readings, and apparently you can't simply measure resistance in a circuit?
But for some of the 10K resistors I get a correct readings and for others not even half of their value.

Even worse for 470k, but after taking it out of the circuit it seemed normal (I measured 3k in the circuit...) then a lot more, but my multimeter is not precise enough

[antonis]

For particular item resistance measurement, you have to trace any possible PARALLEL conection with other circuit items..
(and make complex calculations to estimate expected measurement value only when you're sure about all other items values..) 

Most convenient is to desolder one leg, lift it up and take measurement..

P.S.
You better get a desoldering pump 'cause braid isn't convenient for such jobs..
You can apply a smear of solder on item pad when simultaneously lifting item's side leg via a small flat screwdriver or similar..
With leg lifted, it should be much easier to clean pad hole with desoldering pump..
Hint: Do NOT attempt to use remaining pad solder by just heating pad and pushing item leg back to its initial place unless you're looking for cold joint troubles..

[amaurythewarrior]

I have a pump but it sucks, or actually it doesn't really that's the problem.
I haven't used it much maybe I'm doing it wrong, but I might need to get something better.

[Steben]

I have a pump but it sucks

It should 

Following the thread.... very interested

[amaurythewarrior]

that was my joke, it does but not in the litteral meaning, unfortunately.

I'm gonna take the whole thing apart and order parts, but I have a question maybe that can't be answered.
Are there parts that cannot be damaged, or are very unlikely to have been. I know transistors and ICs are more sensitive, any polarized part I suppose, but what about resistors, or unpolarized caps? I mean, it wouldn't hurt to have some spares, but should I bother?

oh, and I really believe my pump is terrible I mean I get how it is supposed to work but I haven't been able to desolder a single component with it. When I use it on my finger I don't feel anything, the tip has been damaged by heat, shouldn't it be some kind of material that resist heat? I think mine might just be plastic? (the tip I mean)

I have a pump but it sucks

It should 

Following the thread.... very interested

[antonis]

Any item/device can virtually be damaged by exceeding one (or more) of  V X I variables..

Voltage rating is mainly refered on caps, polarity on polarized caps and semiconductors and current on resistors..
Of course, the above is a very brute approach 'cause POWER dissipation is what actually counts - at least for low voltage circuits like pedals..
Electro caps can withstand reverse voltage of a couple of volts or so but, as far as I'm informed, there aren't graphs indicating "damage degree" in function with reverse voltage & time applied.. 
Semiconductors exhibit a variety of reverse voltage withstand, starting form several hundred volts for rectifier diodes and ending down to 5-6V for Base-Emitter junction..
(and even lower for some LEDs..)

Caps in particular don't mind about power rating ( due to 90^o V/I phase difference but this is beyond present discussion..) but resistors DO mind a lot..
(for low voltage use, like in pedals, 1/4W is generally acceptable  for the vast majority of the circuits..)


P.S.
What was the voltage of AC power applied to particular circuit..??

[amaurythewarrior]

The whammy PSU is 9V. That number I did pay attention to, the rest I kinda ignored at the time. For my defense it doesnt' say AC on the adapter (but it does on the whammy)...

So, I understand globally what you're saying but, just to be sure, I'm better buying everything again?
How about pots? Given they are variable resistors, they can be damaged just as well?

[antonis]

Brief answer is NO..
(except perhaps of T2..)

P.S.
Do you really want a working pedal, despite its cure method or a well established troubleshooted one..??

[amaurythewarrior]

I'm not sure I understand your question.
I want a working pedal, but if money was the only concern it would be more productive to buy the whole kit again at this stage ^^
I want to learn more about troubleshooting as well because I don't intend to stop there with DIY.

But if I understand what you're implying, you think there is/there are errors in my build, more than damaged components?

[antonis]

Yes to all..

[amaurythewarrior]

Ah, well in that case, I'll wait before ordering parts.
I'll get a good pump, clean the board with alcohol, and start fresh.
Thank again. And obviously I'll report here.

[amaurythewarrior]

So... I was reading about how to check transistors with an ohmmeter.
I noticed I didn't get the same pattern on T1 (k30a)

Then realized it doesn't say EBC but SGD on the PCB. Which doesn't match the drawing of the component on the PCB, according to spec sheet (http://www.datasheetcafe.com/k30a-datasheet-pdf/). I had put it on the board following the shape, not the letters.

Would it even work at all if it had been the other way around? Is it dangerous to put it the wrong way? (for the transistor I mean)

EDIT: but there's another one that seems to match
https://datasheetspdf.com/pdf-file/643312/Xiaosheng/K30A/1