Hello, I'm new to the forum and looking for help on an electric Yale ERC050VGN. This unit sat for about a year with a bad battery. Finally put a battery in it and the hydraulics will not function. The machine will move forward and reverse, just no hydraulics for steering or operating the lift. There are no error codes that I can tell. Sometimes there is a symbol that will come up on the control with what looks like a cylinder and four arrows around it. Any help is much appreciated.