I have defective UCSB Board, no responses to emails?

[cncdrive]

I've uploaded 3 pictures and marked the points to measure with black circles.
Measure Voltage between those 2 points with a multimeter.
The Voltage should be 5Volts/0Volts when the output is turned on/off in the software.
So, turn the output on, measure, turn the output on, measure.
Do the measurement on all 3 point pairs on the 3 pictures.

[Dazp1976]

No, we do not share the CAD drawing, it would make it possible to copy/reproduce the board.

I do understand that.
Would however be useful to have some kind of basic diagram making probing the correct tracks easier for fault finding.

And... Just as I wrote this I then realised you supplied useful images for the output side.
Thanks.

[cncdrive]

Yes, those measure points are the optocoupler I/O and the buffer chip which drives the output Mosfet transistor.
If you will need any informations regarding the circuit then I could help you ofcourse, we just don't want to share the whole CAD data (Gerber files or PCB file), because that would make it possible to copy the PCB.

[TroyO]

I gave this a shot today, the only one I was able to find was the last one. (It was 4.64 when on, and 4.623v when “off”.)
On the first two, can you post a pic of the whole board and circle the area I need to look at?

I’m not familiar enough with it to find the landmarks.

[cncdrive]

I've made a new picture, the measurement point parts are marked on it with A, B and C.

[TroyO]

Great, I’m sure that will get me there. Thanks!

It may be a couple of days before I can finish the readings. I’ll post back here.

[TroyO]

A Off=.362 On=.297
B Off=4.603 On=4.603
C Off=0 On=4.795

[Dazp1976]

A Off=.362 On=.297
B Off=4.603 On=4.603
C Off=0 On=4.795

I reckon fault on optocoupler marked U6. (inbetween A & C).
The black thing with 4 legs either side of it. The bottom one of the row of 4.
I think A should go off/on same as C but the opto diode is stuck on keeping A with volts, this in turn keeps output on.
I would have a real close look under magnification at the opto legs to see if any bad soldering is touching any of them together.

[cncdrive]

Yes, then the optocoupler (HCPL2631S) is bad or it is legs not contacting to the PCB properly or it's pullup resistor (from point A to 5Volts, it is that small resistor) is bad or not contacting to the PCB properly.