[![enter image description here](https://i.stack.imgur.com/DUnav.png)](https://i.stack.imgur.com/DUnav.png)

I have this design.  

Mounted on "Project Board" and "Universal PCB" it works great.

But soldered in a specially designed PCB only works fine for the first 10 tries, every 2 seconds, high work load.

All 3 versions use same kind of componentes. 

So... I tried to cut off the led attached at input (Led1), and the performance increased 20%, but again fails in 14th try.

It looks like a saturation in moc3021.

I assume:

* R5 ( 220Ohms) is to high?
* R6 (1.5KOhms) is not needed?