I have just connected my brand new board (received this week), and it behaves strangely.

When SW1 is in the recommended (- + + -) (1-2-3-4, correspondingly) position, the lock light is always ON, even when no source is connected (and by that I mean nothing is connected to the receiver inputs at all). When I put it in the (- + + +) position, the light goes OFF and stays OFF.

When I connect a source (the TOSLINK module set to the consumer level and connected to a computer that sends a test signal) to Input 1, I see a decently shaped 0.4V signal on the CIN4 capacitor, but there is nothing at the outputs, and the LOCK light stays OFF (if SW1 is (-+++)) or ON (if SW1 is (-++-).

Both boards are powered by LCDPS (5.25V). Both input selection pins are connected to the ground. Nothing is connected to the outputs or inputs 2-4. EDIT: shorting the unused inputs 2-4 does not change anything.

I would appreciate any suggestions.

Edited by user Saturday, February 4, 2017 9:28:29 AM(UTC)  | Reason: Not specified

OK, I think I know what is going on... Please correct me if I'm wrong, because something like this should not be happening with a tested assembled board...

I noticed that the "RESET (inverted)" pin of CS8416 is actually pulled to the ground even when the board is powered by a 5.25V source. This is the "RESET" state of the chip...

Then I looked at the voltage supervisor. The schematic calls for part # TPS3809K33DBVT (IC 2.93V supply monitor, which makes perfect sense since it responds to VDD, which is 3.3V). Per datasheet, this chip is supposed to have a "PDBI" marking on it. What I see on my board is "PDCI" marking. "PDCI" means part # TPS3809I50DBVT. This one requires 4.55V to flip to 1. There is never 4.55V on that voltage monitor (remember, it's connected to VDD), so CS8416 is always in the "RESET" state (which explains floating pin 14; all other pins that sense voltage on power-up through 47K resistors are probably floating, too).

Here is the datasheet link, you want page 2: http://www.ti.com/lit/ds/symlink/tps3809.pdf .

So long story short, my board has a wrong part installed on it...

Here is a funny part. This is my second board. I got my first board a few weeks ago, but I have managed to spill hot coffee on it before I had a chance to test it. I cleaned it, but it never worked, so I quietly ordered another one. Which also didn't work, but for reasons that have nothing to do with spills. And yes, the first board also has that wrong voltage monitor...

So, please, tell me where I'm wrong and restore my faith in humanity...

Edited by user Sunday, February 5, 2017 5:56:19 AM(UTC)  | Reason: Not specified

Ok. I finally had some time for investigation today.

Long story short: yes, this is exactly the problem. I will be repairing the boards ASAP, and refunding the cost of the kits.

Long story long: I recently ordered some new parts and got the wrong reset chips. A total of eight of the new chips have been used, so this led me to wonder how they passed testing. For this, I have found out exactly what happened.

For reasons I will not go into here (family related), the last batch of ten or so boards were in fact, not tested, so the incorrect parts were not detected.

So, sorry for the mixup.

I will be reaching out to the other folks who have one of these boards and getting them straightened out as well.

Edited by user Monday, February 6, 2017 1:50:54 AM(UTC)  | Reason: Removing some detail

I will contact you via PM on how to proceed.