The layouts are available on the web. You should be able to
see what's happening with just a voltmeter.
With a 3.9V zener and 120 ohm to ground, you should get
3.9V across the zener, roughly, and 1.1V to ground.
Bob
From: "tuk88@rocketmail.com [PolySix]" <PolySix@yahoogroups.com>
To: PolySix@yahoogroups.com
Sent: Friday, January 2, 2015 12:35 PM
Subject: Re: [PolySix] Re: Non-working attenuator
To: PolySix@yahoogroups.com
Sent: Friday, January 2, 2015 12:35 PM
Subject: Re: [PolySix] Re: Non-working attenuator
I've got 3.35 V on pin 2 and 5V on pin 3. Normally, that works fine. But at the output, 0V. So I think that the LM393 is brown.
Howether, I'm looking for this strange voltage on the input 2 of IC5. I think there is a mistake on the Clone PCB. Because the voltage divider looks like to works fine.
I will contact the PCB maker to have the layout picture to check where the trouble come from.
I'll keep you in touch
Lucas
Howether, I'm looking for this strange voltage on the input 2 of IC5. I think there is a mistake on the Clone PCB. Because the voltage divider looks like to works fine.
I will contact the PCB maker to have the layout picture to check where the trouble come from.
I'll keep you in touch
Lucas