EHX POG2 Dry Output not working

CJAudio · Post by **CJAudio** » 24 Dec 2022, 12:50

Hi guys, I'm trying to fix my EHX POG2. The Dry Output control is not working anymore and I'm not getting any dry signal at the output (when the effect is engaged). First I thought that the slide potentiometer was broken, but I measured its resistance and it looks okay to me. I found this POG2 schematic but it seems to be for the HOG2, although I'm sure it's almost the same unit (or very similar) with more features.

I was wondering if anyone had this problem before or can help me debug the problem by following the schematic.

Thanks,
Cris

mauman · Post by **mauman** » 24 Dec 2022, 22:37

1. Does it change if a PRESET is loaded or unloaded?
2. Does the status of the DRY FX button change the result? That determines the path that the dry signal takes.

I agree that this schematic, although labelled POG2, doesn't match the feature set of the POG2.

CJAudio · Post by **CJAudio** » 25 Dec 2022, 12:30

Good ideas mauman.

1. Yes, I get dry signal with a preset
2. Yes, only when I get dry signal by loading a preset

I noticed that by loading a preset and moving the DRY OUTPUT up and down a few times, the signal disappears after a few moves. Maybe I'm wrong and the slider is the problem.

mauman · Post by **mauman** » 25 Dec 2022, 19:51

Most of the controls are just telling the processor what to do, not acting as voltage dividers in the signal path. Without the right schematic I can't tell which the Dry Output slider is doing, but I would suspect the former. The evidence is that loading a preset overrides the Dry Output slider setting, then when you move the slider you lose the signal. I would look at (1) whether the Dry Output slider is properly providing a smooth change in resistance when you move it from end to end, and (2) whether the path from the Dry Output slider to the processor control input port is unhampered (no shorts, grounds, etc.) Most likely (1) since it's mechanical. Maybe a squirt of De-Ox-It D5 or F5, or CRC Contact Cleaner?

CJAudio · Post by **CJAudio** » 25 Dec 2022, 21:15

Yeah I'm aware that the potentiometers are a reference for the processor. I followed the schematic with the PCB and they don't differ that much.
I ended up removing the slider and found out that one side of the carbon track is not connected to the metal pin. I ordered the part already, I hope that's the only problem with the pedal.

Thanks a lot for your help!

mauman · Post by **mauman** » 25 Dec 2022, 23:56

Good troubleshooting!