JYE Tech Forum

Yah, there was a slight positive DC offset in that last photo. I adjusted the vertical position such that it loo balanced now - solid 1KHz square wave with a 50% Duty cycle. Question about power supplies: I’ve been using a 9v battery but wondered if I could use the adapter that comes with the Arduin...

Replaced L2 with a new component - I now have a reasonable looking square wave from the test mode. See attached photo (SEN1 = 0.1v; SEN2 = x5)

One question: the voltage read out in the upper right shows 0.0v. I thought that read out was the max positive voltage but that doesn't seem to be the case.

Thanks for all. I've ordered a few replacement components from Digikey. It'll be a few days until those arrive and I can dive back in to resolve the issue(s).

Rechecked all connections and they seem good. I have to admit though that when I did the initial install, I inadvertently put L2 in the wrong place and had to desolder it to relocate it to its correct spot. Perhaps something happened in that process. Voltages: (-) D2 to gnd 7.74v (+) D2 to gnd 8.50v...

First, thanks a ton for your patient assistance - much appreciated. I currently don't have access to an oscilloscope - not even the one I'm trying to get to work :-( of course - but I will try to borrow one next week. In the meantime, I am rechecking solder connections and I'm using a voltmeter to c...

Thanks for those test procedures. Here are my observations with the battery connected, LCD attached, CPL = DC, SEN1 = 1V, SEN2 = X5 - it appears I'm way off in certain areas: Vbattery = 8.17v Battery is center positive D2 edge = 7.54v V2 = 3.38v V1 = 2.875v AV- = 0.671v AV+ = 4.94v +3.3V = 3.31v +5V...

Are you sure the pack is center post positive?

R26 is spot on 1K. Solder points all visually look reasonable. Finger test doesn't produce the noise signal I would expect to see - the trace remains as it appeared with the probe calibration

(Working with a legitimate board; firmware -061) See attached photo (CPL = AC; Sen1 = 0.1v; Sen2 = X5). The scope boots up fine and a trace appears just above the horizontal axis but I do not get the expected square wave with the red lead attached to the test point. You can't really tell from the ph...

Got it, thank you. I'm move ahead to the next step.