No audio for Deluxe Bass Big Muff π

[pudge]

The LEDs and switches appear to work, but I get no output, not even noise.

If I use the “direct out” as input, then I get output. But nothing through the input, at all.

EHX says they will repair it for $35 (probably not including shipping), so not sure if it is worth it.

Any ideas for how I might try to repair it myself?

UPDATE: more pics of the full PCB, for posterity

 

[Locrian99]

most likely the problem is at a jack or switch connection. Im not familiar with that particular pedal but ive repaired a few ehx pedals where the problem is at the rotary switches. If you cand find a schematic audio probe it.

 

[Locrian99]

I would start by looking at fsb for schematic etc.

 

[pudge]

I would start by looking at fsb for schematic etc.

Thanks, I am new to this, but just found that and no one has this pedal that I can find (I found the regular Bass Big Muff, but not the Deluxe).

Maybe I will just start pulling the PCB out and see what I can see. I am not sure *how* to get it out, but it is similar enough to other EHX pedals that there’s probably some info out there. Any hints for that?

Thanks again!

 

[pudge]

Thanks, I am new to this, but just found that and no one has this pedal that I can find (I found the regular Bass Big Muff, but not the Deluxe).

Maybe I will just start pulling the PCB out and see what I can see. I am not sure *how* to get it out, but it is similar enough to other EHX pedals that there’s probably some info out there. Any hints for that?

Thanks again!

Hm, now that I look at it, I am thinking removing the knobs and footswitches might release the PCB.

 

[Nic]

Does that cap looks suspicious ?

 

[pudge]

Does that cap looks suspicious ?

View attachment 84069

Hm, nice catch, maybe?

I’ll test it later, thanks.

 

[pudge]

Hm, nice catch, maybe?

I’ll test it later, thanks.

If that’s the problem I will be so happy should be simple fix, even for me

 

[Nic]

Not sure that's the problem, but worth looking into.

 

[Nic]

Might be worth checking R68 near power jack.

 

[pudge]

Not sure that's the problem, but worth looking into.

Absolutely. There’s some odd discoloration on top too, that’s probably a bad sign.

 

[pudge]

Not sure that's the problem, but worth looking into.

Any idea of how to remove the PCB? The power jack is in my way. Got all the knobs and jacks taken care of, but can’t figure out the power jack.

 

[pudge]

Any idea of how to remove the PCB? The power jack is in my way. Got all the knobs and jacks taken care of, but can’t figure out the power jack.

Finally got it off. Removed, tested. Cap is dead. Ordering replacement. Thank you!

 

[Feral Feline]

Even if you get it working, you should send it to Robert to trace, and then you'll have a schematic for if anything else goes wrong.

 

[pudge]

Even if you get it working, you should send it to Robert to trace, and then you'll have a schematic for if anything else goes wrong.

I’m new. How would I do that?

 

[Feral Feline]

I’m new. How would I do that?

Send @Robert a PM.

He's a busy guy, so ... If he agrees to it you might be without your pedal for a few weeks or so, but you'd get it back and possibly eventually a PCB as well, to roll your own.

There are quite a number of bass players on the forum, and we're always looking for projects with MOAR BASS!

 

[Locrian99]

Does that cap looks suspicious ?

View attachment 84069

Nice catch!

 

[Feral Feline]

BTW, Pudge, inspect that other electrolytic cap north of the one Nic circled — if it or any other electrolytics are bulging, you may as well replace them as well.
Don't forget Nic's other catch, the eye-spy-with-ohmy-a-little-fried R68.

EDIT:

https://www.reddit.com/r/basspedals/comments/1abbpjx/i_need_help_fixing_my_deluxe_bass_big_muff

https://www.reddit.com/r/basspedals/comments/1g4jqno/deluxe_big_muff_pi_blew_up

This is the email I got back from ehx.
Electro-Harmonix Poster@ehx.com wrote:
R68 on the Deluxe Bass Big Muff is a 10-ohm, 1/4W resistor but maybe you should buy a 1/2W resistor so that it doesn’t blow again:

https://www.mouser.com/ProductDetail/Vishay-BC-Components/SFR25H0001009JR500?qs=sGAEpiMZZMsPqMdJzcrNwhQJZ0WrEwnKG6ecFijDOP4%3D

 

[pudge]

BTW, Pudge, inspect that other electrolytic cap north of the one Nic circled — if it or any other electrolytics are bulging, you may as well replace them as well.
Don't forget Nic's other catch, the eye-spy-with-ohmy-a-little-fried R68.

EDIT:

https://www.reddit.com/r/basspedals/comments/1abbpjx/i_need_help_fixing_my_deluxe_bass_big_muff

https://www.reddit.com/r/basspedals/comments/1g4jqno/deluxe_big_muff_pi_blew_up

Good idea. The other caps look fine, but MAYBE a TINY bulge on the one just north of the bad one? (I am getting 20 of them, so, whatever, I could replace that too.)

Will look into R68. Trying to figure out what it is.

 

[pudge]

Good idea. The other caps look fine, but MAYBE a TINY bulge on the one just north of the bad one? (I am getting 20 of them, so, whatever, I could replace that too.)

Will look into R68. Trying to figure out what it is.

Looks like that reddit link has some links to that part.