Strange behavior CTS 288 encoder

[kurt-olsson]

Hi.

I am having some trouble with some of my encoders.
Sometimes the values flickers and sometimes i cannot increase or decrease.
The thing is, if i touch the cables connected to the encoder with my hand it starts to work flawlessly.

It must be something with my ground connection or do anyof you have an idea?

this happens only on two specific encoders, the rest are always working fine.

I don´t think it is the encoder itself that is bad.

where should i start debugging?

[fordgt40]

Do you mean touch the encoder contact or touch the insulated cable. If the latter, then it is likely to be a dry solder joint. Try re-soldering the joints on affected cables - just touch them with a hot iron and a little solder. Always try the simple things first 

David

[kurt-olsson]

Hm, good question, i think it is the contacts but it might just do touching the cables as well.

But i will try to resolder the contacts, it would be better if the problem is in the cables than some common ground problem...

[Sam Llorca]

Humm,  interesting,  that's how my MCP started malfunctioning,  it'll be good to know your finding,  please share if you find the problem,  thanks.

[RayS]

I always thought it was a cold solder joint or a joint that didn't flow correctly during assembly on Sam's old MCP. Lead-free solder is more sensitive to constant heating-cooling cycles and will eventually separate on connections that are flowed properly. I just couldn't see 2, 3 encoders all going bad at the same time.

[kurt-olsson]

True, why wold them all fail at the same time, and it dont think the teensy card is busted either.

i will try resolder tonight, i will update this thread with the result. =)

[kurt-olsson]

The problem is in the soldering, connections / cables. i just resolder and tighten up some ground soldering and it works.
I think this flickering and not rotating is a sign of not grounding working 100% correct.

My MCP is a total hack, i will redo everything when i have the time and do it more correct with a metal ray for + and one for - and not go component to component with the ground wiring. And also i will use ribbon cables, proper IDC connections instead of just soldering and tape it.

[kurt-olsson]

100% confirmed, it was cold-soldering that was the problem. resolder more thorough and it works perfect.

[Sam Llorca]

Great, good to know Peter.