Large number of flickering/ghost inputs on Master Cards

Hi Jack/Les

The expansion board was posted Saturday am, first class signed for delivery. Lets hope that this determines the root of the problem :p

David

Hi David,
Jack has a curly one eh. Cant believe he has 4 faulty M/C's.
Nice to see you around and ever so helpful as usual.
Have a nice one
Les

Hi David,

Thank you very (!) much, I shall inform you of the reception of the card and let you know the results.

If you are willing to of course, would it be worth me sending one or two of my master cards back with your USBExpansion card for you to test with your setup? That would also eliminate a MC card problem if they work fine with your setup (I would include return stamps of course).

I am still convinced there is something amiss with my wiring although I am not sure what, and this still does not explain why only with J3 does the problem occur.

Jack,
At least you can rule out the usb exp bd. I did have a case once with another I/f kit Fsbus that did something similar,
never did get down to the bottom of it.
I still have a sneaking feeling that cabling is the problem. But you don't want to go down that path till everything
has been exhausted. Have you sent your pics to O/C yet?.
Les
P.S J3 is a mystery but I have seen many like this in electronics and even Engineers
that have designed it could not provide an answer.

Hi Les,

Unfortunately I am unable to take any photos at the moment due to the lack of (any!) working cameras in the house.

If David's USBExpansion doesn't yield any new findings, and the new PSU doesn't work, we will be redesigning out master card "stack" such that there is no crossing of wires, etc. However, I don't know how we can solve the problem of wiring at the end of the overhead panel, because it is what it is!

Don't loose faith Jack, the thought of redoing things is usually worse than it really ends up.
If you have to then there are many guys who have build o/h using O/C that im sure you could
get some inspiration from.
Lets not get ahead of ourselves.
Just one thought, if you have used shielded cable, by chance you have not connected it to
what o/c call GND. Its not really what GND for usually stands for. Ie its not a ground for shielding purposes but a common for switches.
Lets just wait and see if David's board helps.
Les

Hi Jack

I do not believe that all your mastercards are faulty. It is difficult to keep track of the actions you have taken, but have you moved the J3 connector and its associated switch wiring to a J2 connector to see if the problem followed you?

Sorry, but I do not want to dismantle my arrangement to test your mastercards as I think there is no real need and it will be a fair bit of work and risk for me - once you start "tinkering" all **** can break loose :D

My money is on either a faulty expansion board or the wiring to J3.

The easiest way to test the wiring to J3 is to release all the ground leads to the "breakout board", test for flickering. If none, then reconnect each single ground wire in turn, testing each time for flickering. If/when the flickering returns, then carefully check the wiring in that bank. Also make sure that any defined outputs are actually connected to a led, if not then delete the variable referencing that location

Regards

David

Jack

Les`s post about "gnd" has raised another issue. I assume that on your wiring you have not mixed up chassis gnd with "signal gnd" The "gnd referred to in the "input banks" and the gnd for the "outputs" should always be wired separately and are not power "gnd". OC cards may suggest that they are common but you should not wire them together yourself.

David

Hi,
i had a simular problem or at least the symptons are simular. When testing my OC USB exp board with 1 MC attached I saw all flickering things in sioc monitor.I could not find a cause so I putted the whole bunch in a drawer. Some months later I retried and it was working. The reason why all started flickering in sioc was that I had tried three connectors on the USB exp board except... MC connector nr.1 So the resume: check the MC which is connected with the first MC connector on the USB exp board. If you connect a MC to MC connector 2,3 or 4 without a MC attached to that first MC connector it flickers al over.

The expansion card has four mastercards attached already