Millenium Bypass Vero Layout Problems

Started by bussche, March 06, 2010, 03:55:23 PM

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bussche

I am having problems with this layout for the milenium bypass.  The dppt switches between the effect and bypass fine but the led does not light up.  As far as I can tell all my connections are sound and the orientations for the components are correct.  Has anyone had success with the layout?  Thanks.

bussche


R.G.

Before you get too worked up about your wiring, test the millenium all by itself.

Try temporarily connecting a 1M resistor from ground to the control line. When the LED is on with the resistor not connected, and off with the resistor connected, then try connecting it to your bypass switch. The millenium is a sensitive detector of the difference between really open circuits and resistances to ground of 1M or less.
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

bussche

I've discovered that the LED is fried...not sure if it was something I did when I was trying different things to get the circuit to work.

Now I've replaced with a new led, which lights up in both positions of the switch!  If I disconnect the ground from the millenium circuit then its on dimly when the effect is bypassed and off when the effect is on.

Any ideas?

R.G.

Quote from: bussche on March 06, 2010, 09:02:50 PM
I've discovered that the LED is fried...not sure if it was something I did when I was trying different things to get the circuit to work.

Now I've replaced with a new led, which lights up in both positions of the switch!  If I disconnect the ground from the millenium circuit then its on dimly when the effect is bypassed and off when the effect is on.

Any ideas?
The Millenium has been thrashed through by many, many people here. It's all over the archives. Common mistakes are:
1. Getting the MOSFET backwards. There are more than one pinout, so you have to get the datasheet for YOUR MANUFACTURER'S BS170. Your layout seems to match the Fairchild BS170, but I don't know what brand you used. If you get the MOSFET backwards, the LED will always be on, because MOSFETs have an inherent, built-in reverse diode that conducts in the reverse direction.
2. Oddities about the pullup diodes. Sometimes the diodes don't leak enough, so you need maybe two in parallel. That's if it won't turn on.
3. general miswiring.

Do this. Disconnect it from the switch. Power just the millenium, and solder one end of a long lead 1M to ground on the millenium board. Bend the 1M so you can press the other end to the control line by touching the body. Get the millenium running so that when you press the 1M to the control, the LED goes out, and when the 1M springs away from the control line, the LED goes on.

The Millenium 2 does not have issues with dim lighting of the LED like the Millenium 1.
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.