This seems to be a real head scratcher but shouldn’t be.
What I have is a press, upper and lower cylinders that come togethor to form powdered wax into a candle. System has been in production for around 5 years. Well last week the upper cylinder wouldn’t come down more then a quarter inch before it gave a following error. After come investigation I thought the problem was simple, we have a PO check on the upper cylinder so it don’t fall down under a power loss situation. Took that out of the system and nothing changed. Cylinder will fall now when you lose power. It will go back to full retracted just fine but won’t extend. It goes to Output Saturated. With my meter I can only read a 3.5Volt coming out of the output, but I’m wondering if my meter isn’t fast enough to read it.
The bottom works fine, but the top won’t extend.
Switched valves, no change.
Switched Wires no change
flopped the hoses on the valves, put upper on the lower and lower on the upper. Top would jump around crazy and bottom wouldn’t extend. I think that’s because the stroke of the bottom cylinder is about half of what the upper is.
Now we are back to original configuration and problem is right back where it was, I’m convinced it’s not a RMC problem but a physical hydraulic problem.
Out of ideas now, can anybody see anything that I’m missing? Of course we needed this thing running last week.