I still think it is the controller. Think simple, mechanical first, electrical second. I would start with the rubber button graphite contact. I may have warn off. That is where that kit helps, it contains new contact material. First figure what two points the graphite touches to make the contact. Touch those two points with a small wire. If it works then get the kit. If not, check out the cable with an ohm meter, contact by contact to see it it is good. Check out the plug sockets it same way to see it the wires are good. I would think that if the opposite button works it is wiring because they probably do a simple reverse polarity to control the other button (positive makes the motor run one way, negative makes it go the other way). There are not enough wires in the cable to have 6 of them just for direction. It is probable 2 wires plus a ground (one wire for up/down and one wire for left/right).

Do you know anyone with an autostar unit. You could use theirs to figure out if it is controller or cable.

Last resort, open the base and look for a broken wire. The motor probably has only one or two wires (if one it uses the base as ground for the second contact. Check those first, There should only be one gear (the motor changes direction, not the gear), check out Mikes's site and see if it has a diagram.

Good Luck, Bill