What to do when it doesn't work

[R.G.]

Aron, and Peter,

Could we get a new sticky up over the forum on what to do when it doesn't work? I'm counting about three a day posts that all go something like

I just wired up a new MechaBlitz SuperBasher and it doesn't work. I followed the layout/pcb/instructions at JoesToplessBurgerAndEffects.com exactly, and I know everything is correct, but it still doesn't work. What could it possibly be??

It would save us all - including most especially the originator - a lot of time if they knew what to do when this happens; and it's the same thing every time.

(a) Get your mind right. Mother Nature does not lie, but she is a stickler for details. If it was put together perfectly, it would work. It not working is Mother Nature's way of telling you that you made some tiny error, and it's no reflection on you if it's not perfect the first time.[/list:u]

(b) Have the proper tools for debug. If you don't have a multimeter capable of reading at least 0-20Vdc and ohms, there is really little chance of getting something working that has a bug. That's as true for me over 30 years after I first picked up a soldering iron as it is for a beginner. In fact, I would recommend a beginner buy a meter **before** buying a soldering iron. It's just as necessary, just in a different order.[/list:u]

(c) Do the first steps first: before posting, hook up the DC power to the circuit, no input signal or amp needed, and clip the meter black/negative lead to signal ground. Probe **every** pin of each IC, transistor and zener diode (if any), making a list of the voltages.[/list:u]

(d) Now post. Post the list of voltages along with a request for help interpreting them.[/list:u]

(e) Learn. There are certain things that always determine what's working and what's not. Read the postings of others that have posted their voltages and find out what happened to them. That way, you get the benefit without having to make the mistakes. Read the debugging page for the indicators about what voltages indicate about function. This last takes a long time, but it's the most rewarding.[/list:u]

I'd be happy to write up the process in some detail. This ought to be a first step for posters. This is NOT newby bashing - it's just an orderly way to help them faster.

[forbin80]

You should add a step in there for after taking readings and before posting:  Search!

[aaronkessman]

i agree. I built a tubescreamer with a PCB i bought from JD at GGG and it didnt work. All the wiring was right and most of the circuit passed signal OK, but after a long time of furious inspection i noticed that right before the first opamp one of my wires had shorted to ground - not because of bad soldering or messy lead dress, but cuz there was a hairline trace of solder on the edge of the board that *shouldnt* have been there but was, and it was leading to ground.

debugging is sometimes painful, but you gotta go through all your possibilities first.

[Dragonfly]

Aron, and Peter,

Could we get a new sticky up over the forum on what to do when it doesn't work? I'm counting about three a day posts that all go something like

I just wired up a new MechaBlitz SuperBasher and it doesn't work. I followed the layout/pcb/instructions at JoesToplessBurgerAndEffects.com exactly, and I know everything is correct, but it still doesn't work. What could it possibly be??

It would save us all - including most especially the originator - a lot of time if they knew what to do when this happens; and it's the same thing every time.

(a) Get your mind right. Mother Nature does not lie, but she is a stickler for details. If it was put together perfectly, it would work. It not working is Mother Nature's way of telling you that you made some tiny error, and it's no reflection on you if it's not perfect the first time.[/list:u]

(b) Have the proper tools for debug. If you don't have a multimeter capable of reading at least 0-20Vdc and ohms, there is really little chance of getting something working that has a bug. That's as true for me over 30 years after I first picked up a soldering iron as it is for a beginner. In fact, I would recommend a beginner buy a meter **before** buying a soldering iron. It's just as necessary, just in a different order.[/list:u]

(c) Do the first steps first: before posting, hook up the DC power to the circuit, no input signal or amp needed, and clip the meter black/negative lead to signal ground. Probe **every** pin of each IC, transistor and zener diode (if any), making a list of the voltages.[/list:u]

(d) Now post. Post the list of voltages along with a request for help interpreting them.[/list:u]

(e) Learn. There are certain things that always determine what's working and what's not. Read the postings of others that have posted their voltages and find out what happened to them. That way, you get the benefit without having to make the mistakes. Read the debugging page for the indicators about what voltages indicate about function. This last takes a long time, but it's the most rewarding.[/list:u]

I'd be happy to write up the process in some detail. This ought to be a first step for posters. This is NOT newby bashing - it's just an orderly way to help them faster.

100% agreed...my EA trem "not working" thread was extremely short, simply because i posted the necessary voltages and took the time to list some of the things i had already tried in the "debug" process. You (R.G.) were able to pinpoint the problem area quickly, and i got it working in almost no time at all !  I believed that the combo saved lots of unneccessary frustration because you were able to diagnose the problem due to having the proper info. (though im sure i could have included more info...)

A sticky on the "debug" posting procedure would be very helpful....you could almost have a info "template" to follow in the debug.

something like:

battery voltage
q1 voltage readings
q2 voltage readings
q3,q4 etc voltage readings
ground been checked and tested
electroliytic caps polarity verified

etc,etc,etc...


BTW, R.G.    ...your help with my EA trem was GREATLY appreciated, and you explained it in a way that was easy to comprehend...and now i understand the circuit a bit better than when i started building it !


andy

[Peter Snowberg]

Thank you R.G., I'll get something up today.

The level of assistance you provide is pretty spectacular.

[Dragonfly]

The level of assistance you provide is pretty spectacular.

...and thats an understatement !!!

[RjM]

The process wrote up in detail that us mere mortals can understand would be appreciated, as well as beneficial to all beginning to make stompboxes, or even those who have built a couple and still are having trouble with a project. Great idea, R.G.


Sticky this quick Aron!

[RDV]

I want a schem 4 that thar MechaBlitz SuperBasher!!



RDV

[RjM]

Sparkleboost

Q1

D- 0.01
G- 0.02
S- 0.01

So... What do these readings mean? Can anyone assist me?

Yeah... I'm stumped. I definately want to get this circuit going.

[petemoore]

Whew...I was hopeing someone would 'formally' request that. Great suggestion.
 By the way there's something wrong with...something..., can you help me right away

[aron]

I'd be happy to write up the process in some detail.

Send it by and it will be sticked!

[R.G.]

Thank you.

Now, having ranted, I'll punish myself appropriately by having to follow through... 8-)

[R.G.]

Sparkleboost

Q1

D- 0.01
G- 0.02
S- 0.01

So... What do these readings mean? Can anyone assist me?

This means that you're not getting any +9V to the JFET, or so little that it doesn't matter. Something is such a high resistance that not enough current gets through the JFET to pull the source up by the volt or so that would start turning the JFET off and let it stabilize, so it just sits there saturated.

Second step: Use your voltmeter, negative lead clipped to ground and probe the +9V on the board (wires to batteries break), the top of the 100K pot, the wiper of the 100K pot, the bottom of the 100K pot, and the drain of the JFET. Yep, we're walking down that conductive string, looking for where the voltage stops. When we walk past the end of the 9V, we have just passed the problem.

[NaBo]

I want a schem 4 that thar MechaBlitz SuperBasher!!



RDV

lol, no kidding!  sounds pretty frickin' harsh!!!  :twisted:  ...

[Peter Snowberg]

I want a schem 4 that thar MechaBlitz SuperBasher!!



RDV

I think that's probably the only pedal with 18 gain stages.  :twisted:

[aron]

'll punish myself appropriately by having to follow through...

HEHEHEHE, you knew I was going to call you on that one!  :twisted:

[RjM]

If the leg of something was touching the side of a capacitor, not the lead of a cap, would it short?

[brett]

If you're talking metal can electrolytic capacitors, you sure can get a short circuit.  But greencaps, MKTs, etc that are in insulated cases are ok.

cheers

[Fret Wire]

Many of these questions don't even have the ckt named, so how about adding:

The name of the ckt you're debugging

A link to the schematic, layout, and wiring diagram

Any substitutions you've made to the ckt values.

If it's a PNP fuzz, whether you've wired it up neg ground or not.

[R.G.]

You should add a step in there for after taking readings and before posting: Search!

Yep - realistically, though, that's probably part of the "learn" phase.

A sticky on the "debug" posting procedure would be very helpful....you could almost have a info "template" to follow in the debug.

'Atsa good one, it's going in there.

Many of these questions don't even have the ckt named, so how about adding:
The name of the ckt you're debugging
A link to the schematic, layout, and wiring diagram
Any substitutions you've made to the ckt values.
If it's a PNP fuzz, whether you've wired it up neg ground or not.

Good!!

Keep it up - I'll be able to just cut and paste... 8-)