Spa will not power on at all; control panel is completely dead, no lights or display.

Safety first: This involves mains voltage. If you are not experienced with electrical work, contact a licensed electrician or spa technician. Always turn off power at the service panel before opening any electrical enclosures.

• 1. Check GFCI breaker: Locate the spa's GFCI breaker. If it is tripped, reset it once. If it trips immediately, do not keep resetting; there is likely a fault.
• 2. Verify supply voltage: Using a qualified electrician, confirm that the correct voltage (typically 240V for most PDC Spas models) is present at the spa disconnect and at the control pack input lugs.
• 3. Inspect main connections: With power OFF, remove the control pack cover and inspect the main power lugs for loose screws, discoloration, or melted insulation. Tighten loose connections to manufacturer torque specs.
• 4. Check internal fuses: Many PDC Spas control packs have one or more fuses on the circuit board. With power OFF, remove and test fuses with a multimeter. Replace only with identical type and rating.

If the spa remains dead after confirming power and fuses, the control pack may have failed and should be replaced or repaired by a professional.