Epson Dot Matrix Repair Needed

My Epson dot-matrix unit has suddenly stopped behaving as it should and I need a technician who knows this older technology inside out. I’m not yet sure whether the fault is mechanical, electronic, or driver-related, so the first step will be a thorough diagnosis... (Budget: $30 - $250 USD, Jobs: Electronics, Firmware, Mechanical Engineering, Printer Repair, Technical Documentation, Technical Support, Troubleshooting)