EgoDriver Error

[metfreak]

Hello,

I've recently built Egodriver and run into a problem... The pedal's working for about 5-10 seconds and that just runs out of volume. I've checked the soldering it seems fine to me, I've doublechecked the values of caps, resistors, pots, actually everything... The thing I noticed when I'm playing in LED clipping mode only one is "shining"? Maybe there's a problem?

Any suggestions?

Thanks

[madbean]

What type of LED are you using there? And, did you follow the instructions on how to correctly hook those up (with a jumper wire)?

[metfreak]

I've jumpered them like it's shown in the .pdf file.

I used this type of LEDs => http://www.banzaimusic.com/LED-5mm-white-ultrabright-1000mcd.html

[madbean]

Does the problem occur only when you have the LEDs selected or does it happen either way?

[metfreak]

Yeah it occurs either way.

[oldhousescott]

Sounds like the input to one of the stages is drifting up toward the rail or down to ground. That would explain why only one LED is lighting up, and also why the sound fades out.

It might be hard to check voltages for troubleshooting as the meter will complete the circuit, but if you have access to a multi-meter, can you provide the voltages at all the pins on the IC with respect to ground?

[metfreak]

Sorry no access to a multi-meter, any other option? Man I want to get that thing start working! 

[madbean]

Can you provide a couple of pics of your build? We'll need to do some guesswork since we don't have voltages. Pics may help in diagnosing the problem.

[metfreak]

I've shot some pictures, if there are any different or closer look you want to get, tell me I'll provide new pictures.

[madbean]

Okay, from what I can tell it looks like the LEDs are hooked up correctly. I think what you should do first is gently apply your heated iron the the solder joint where your wire connects from the LEDS to R3 on the left side of the board. Lift that wire out of place to disconnect it from the bias voltage. Now try testing the build out again and flip the switch to the other side (the side that uses the 2n7000 transistors for clipping). Do you get solid signal now, or does it continue to cut out?

[metfreak]

OK, I'll try to do just that, when I get to my solder kit and will report right back.

[metfreak]

I did what you told me, and it actually worked for like a minute and it went right off again as soon as I wanted to reply :/

And I noticed something funny when I roll volume knob all the way it gets no buzzer... So it's totally quiet when on 0 and fully open!?

[jkokura]

Wow, it seems like there's a big problem going on there.

It sucks, but really the only thing we can recommend is that you go over it with a fine tooth comb again and again.

- Check all your parts are the correct value and are oriented correctly.
- Check all your soldering joints and resolder any that look suspicious.
- Use a DMM to check EACH of your joints connects ONLY to the parts it's supposed to. Use the Schematic and pencil in check marks. This way you can find a part that may be connecting to ground that may not supposed to, or a part that's not connecting where it is supposed to.

Using an audio probe is less helpful in this particular instance because it seems more like you have a power issue. I think you have a leak to ground or a misbiasing issue, meaning that your power is getting to ground or is not dividing properly. It works for a short time because Caps charge up under power, then release the power in a regulated flow sort of manner. I think that's why you have a few seconds of operation, then it stops because something is happening that is breaking or disrupting your power flow. I can't verify that from here though, only you can.

We are here to help in some ways, but ultimately it has to be you that fixes the problem. Wish I could help more, as does Brian I'm sure.

jacob

[metfreak]

Ok, I borrowed a multi-meter, so can someone help em with how should I measure voltage on IC as oldhousescott mentioned?

@jkokura: thanks for all the effort! I can see something is really wrong! I'm working on it for like 3 straight days, but still no result and I'm not gonna leave it at that!

Can you please tell me what is a DMM, so I can check?

Nejc

[gtr2]

DMM is a Digital Multi Meter

To measure voltage at the IC you place the red probe on a leg of the IC and the black probe on ground.

Do this for each pin of the IC.  You can follow the datasheet for pin numbers http://html.alldatasheet.com/html-pdf/9333/NSC/TL082/36/1/TL082.html

Josh