Hello, We have a first edition Sumitomo sh60 excavator. The controls are non existent. Checked the fuse and it is ok, the machine tracks ok but that's about it. Can't move the jib, bucket or slew it around. We know there is hydraulic oil getting to the rams because one of them has a slight oil leak and it leaks as usual when we move the controls... It's something electrical, but where to look if anyone knows? Thank you.
I'd check the gate lock solenoid (sometimes called the pilot shutoff solenoid) I think the easiest way to test it is to find the solenoid (usually near the main control valve), unplug it, and check if it's getting 12V when the gate lock lever is up. No voltage? Then you're chasing a bad switch or a broken wire. Has voltage but solenoid doesn't click? The solenoid itself is probably toast. Also maybe check your pilot pressure relief valve while you're in there. if it's stuck or worn out on an older first-edition machine, you'd see the same symptoms.