Abyss

[servusjon]

Built the Abyss, but for some reason the yellow LED doesn't flash but lights constantly fairly weak. Also I can hear no modulation. Any ideas?

 

[Heisenberg]

Hello folks,

I'm a noob in electronics but I've built a few kits already and I'm having a similar issue to the one described above (I didn't want to open another thread as this one is fairly recent).

My problem is the following:

* The indicator LED doesn't light up when toggling the effect;
* Initially I thought only the boost stage was working, after reading this very thread I've tested flashing a torch on the photo-resistors and the effect kicked in;
I don't have a spare LED to replace the internal one right now, but considering the the external LED is also not working, I'm wondering if the problem might be somewhere else.

In the attached image, you'll notice that I've removed the internal LED already (and the 25k pot is not soldered because of that)



Thanks

 

[Chuck D. Bones]

Any chance you wired both LEDs backwards? It's an easy mistake to make. I know, because I did it on my last vero build. Killed the LED too. It's always a good idea to order spare parts, you will need them. I suggest you check these things:
- Make sure the transistors are tight in their sockets.
- Carefully inspect all solder joints under magnification.
- Verify all components are the correct value.

 

[Heisenberg]

Any chance you wired both LEDs backwards? It's an easy mistake to make. I know, because I did it on my last vero build. Killed the LED too. It's always a good idea to order spare parts, you will need them. I suggest you check these things:
- Make sure the transistors are tight in their sockets.
- Carefully inspect all solder joints under magnification.
- Verify all components are the correct value.

Hey Chuck, thanks for your help. I did all what you suggested, triple checked all the component's values, the transistors are firmly in place and I verified all the solder joints and redid a few that required and replaced the LEDs with new ones. Still, the exact same issue, the LED's don't light up, but if I point a flashlight to the photoresistors the effect works.

Any other suggestions?

Thanks again.

 

[Chuck D. Bones]

With INTENSITY all the way down and VOICE all the way up, you should get a pretty bright glow out of D2. Did you read this article? There's not much that can cause both LEDs to be off except installing them backwards. If you have a DVM, then set the controls per the first sentence in this post and measure the voltage at each pin of Q2. Should read something like this:
E: 4.4V (pin closest to C15)
B: 5.0V (middle pin)
C: 7.4V (pin closest to RATE pot)

 

[Heisenberg]

With INTENSITY all the way down and VOICE all the way up, you should get a pretty bright glow out of D2. Did you read this article? There's not much that can cause both LEDs to be off except installing them backwards. If you have a DVM, then set the controls per the first sentence in this post and measure the voltage at each pin of Q2. Should read something like this:
E: 4.4V (pin closest to C15)
B: 5.0V (middle pin)
C: 7.4V (pin closest to RATE pot)

Hey Chuck, thanks so much for your time and patience.

The LEDs are indeed inverted ?‍ . I was following the build guide here and it shows the LEDs as the symbol #3 from the article, so when I installed following the build guide they ended up inverted as the in the PCB, the orientation follows the symbol #1 or the new standard. Thanks again, I'll re-re-reinstall them LEDs and I'll update here for future reference.

Cheers.

 

[Chuck D. Bones]

I would not reuse LEDs that have been installed backwards. Reverse voltage damages them. 4 possible outcomes:
1. LED is dead, no light comes out
2. LED performance is degraded, light output is not as strong as it should be
3. LED is "walking wounded" - it works now but may fail at any time
4. LED functions according to spec, you dodged a bullet.

#4 is the least likely.

 

[Heisenberg]

I would not reuse LEDs that have been installed backwards. Reverse voltage damages them. 4 possible outcomes:
1. LED is dead, no light comes out
2. LED performance is degraded, light output is not as strong as it should be
3. LED is "walking wounded" - it works now but may fail at any time
4. LED functions according to spec, you dodged a bullet.

#4 is the least likely.

Can confirm that the LEDs orientation was the culprit. The old LEDs were working fine, it seems, but I replaced both with new ones anyway, now the pedal is working perfectly.

Again, thanks Chuck for your time and prompt help!

 

[Chuck D. Bones]

You are very welcome. Good to hear you got it working. Now you can play "Bridge of Sighs."

 

[chongmagic]

I tell you what I always do, after building so many pedals and getting the orientation incorrect. I always just put the LED into the holes and bend the leads so that they contact the solder pads. I will hook up the power leads to a testing board I have and see if the LED lights up. If not I either have it in backwards or something else is wrong. But in the end it saves a lot of time.

 

[zgrav]

I do the same thing with the LED orientation. Test it to get it to light up before soldering.

 

[chongmagic]

Yeah bad experiences led me to this, I was building a tremolo and it had an internal LED that I installed backwards. Ended up ruining the board by trying to desolder the LED.

 

[Heisenberg]

Yeah, lesson learned. From now on, sockets everywhere. Even though I couldn't really find them at the local store here in NZ .

 

[Chuck D. Bones]

HA HA HA HA. You should even socket the sockets, just to be on the safe side.

But seriously folks, I only put in sockets for parts I know I'm going to change: EEPROMs & Germanium transistors. Sockets can cause as many problems as they avoid. Here's a way to protect the board when you're removing a part: cut the leads on the part first. Now you have better access to the solder pads and you only have to unsolder one lead at a time. The parts is destroyed, but it was probably fupped duck anyway, so no harm. That's how the pros do it.