If it is a HWH control box problem, not turning on the pump like I just experienced, there are a couple of procedures I have found on this forum in the past. These will bypass the control box, allowing the pump to run. You can then use the slide retract button.
Years ago a member named Wayne R wrote about how to build a bypass box to operate the jacks and slides in the event the control box fails. But that doesn't do you any good at the immediate moment. But the above procedures might help.
If not electrical, there is manual procedure involving releasing the pressure on the slide solenoids and using brute force to push it in. Not fun. But bedroom slides are easier to push in manually than the living room slide. The jack solenoids have a Tee handle, the slide solenoids have a hex nut to loosen. Beyond that I can't help you identify which solenoids for which slide.
'04 Alpine Coach 36' MDDS