Phase II issues

Ale_jellybelly

Well-known member
1. The yellow led doesn't light up in a smooth sine wave but the rise time is very fast, I can only control the fall time with the pots and trims
2. The led stalls when the rate is very slow, it stays on

What could it be?
Pics (I know, I need to remove some flux)
PXL_20260726_173833295.jpg PXL_20260726_173936928.jpg PXL_20260726_173949189.jpg PXL_20260726_173957201.jpg
 
1. The yellow led doesn't light up in a smooth sine wave but the rise time is very fast, I can only control the fall time with the pots and trims
2. The led stalls when the rate is very slow, it stays on

What could it be?
Pics (I know, I need to remove some flux)
View attachment 121552View attachment 121553View attachment 121554View attachment 121555
Looking at your pictures, could it be some solder residues shorting a soldering pad with another pad or with a nearby pcb trace ?

You can try to clean the board by vigorously brushing the pcb's soldering side with a dry toothbrush until you cleared most of of the soldering residues.
You can also clean the little spaces between pads, using the tip of your soldering iron. Move quickly to avoid overheating the pcb.

The best for residues would be some pcb cleaner spray, i use something with a brush on the tip and it's very effective to clean pcbs. To be used outside the house and maybe with a protection mask on, because it's full of chemicals.
1785098046165.jpeg
in red, some solder residue examples.
In blue, a possible short.
The right pad looks like there's a bit too much solder and it could be touching the next pad on the left.
 
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