Quick answer: Candela GentleMax Pro fault codes include 1.1 and 1.2 (handpiece/canister bubble circuit), 2.1 and 2.2 (system hardware test), 3.1 (shutter fault), 4.2 and 5.1 (power supply communication and tolerance), 6.1 and 6.2 (calibration), 14.1 and 14.2 (power supply), and 15.1 (power issue). Each code points to a specific component. Power supply faults usually mean HVPS testing or replacement, calibration faults often trace to dirty or worn optics, and shutter or bubble circuit faults usually need a delivery system inspection.
If your Candela GentleMax Pro is displaying a fault code, the number on screen is the fastest path to diagnosing the problem. This guide covers the documented fault codes for the GentleMax and GentleMax Pro platform: what each one means, what's likely causing it, and what to do next.
Fault codes below are drawn from Candela's official GentleMAX operator's documentation (doc. 8501-00-1810) and corroborated by independent laser repair technicians. Always confirm with a qualified technician before replacing parts.
Handpiece and Delivery System Faults
Fault 1.1, Handpiece Bubble Circuit
What it is: The handpiece bubble circuit test did not detect a change in signal during system check.
Likely causes:
- Delivery system fault or internal break in the fiber/cable assembly
- Loose or failing handpiece connector
What to do:
- Power cycle the system off for 5 seconds, then restart.
- Retest the handpiece. If the fault clears, monitor for recurrence.
- If Fault 1.1 returns, the delivery system needs replacement. This is not user-serviceable.
Fault 1.2, Canister A Bubble Circuit
What it is: The canister bubble circuit test failed to detect a signal change, indicating a Canister A malfunction.
Likely causes:
- Canister A hardware fault
- DCD (cooling) system component failure
What to do:
- The system will automatically fall back to Canister B. Continue operating on B in the short term.
- Schedule servicing for Canister A; do not rely on the workaround long-term.
- If the problem persists after service, contact PhotonX for diagnosis and parts.
System Hardware Faults
Fault 2.1, System H/W Test (ROM Checksum Failure)
What it is: A checksum failure detected on system ROM during the hardware self-test.
Likely causes:
- Transient software/memory error
- Failing control board
What to do:
- Turn the system off for 5 seconds, then restart.
- If the fault clears, no further action is needed.
- If the fault persists, contact PhotonX for diagnosis and parts.
Fault 2.2, System H/W Test (VRef Check Failure)
What it is: A reference voltage check failure. The fault message specifies the affected module and the expected vs. actual measurements.
Likely causes:
- Voltage reference drift on the named module
- Failing component on the control or power board
What to do:
- Turn the system off for 5 seconds, then restart.
- Note which module is named in the fault message.
- If the fault persists, contact PhotonX for diagnosis and parts.
Shutter Fault
Fault 3.1, Shutter Fault
What it is: The shutter is not in the correct position when checked and does not respond to actuation.
Likely causes:
- Mechanical obstruction or jam
- Failing shutter motor or actuator
What to do:
- Turn the system off for 5 seconds, then restart.
- Retest. If the shutter responds normally, monitor for recurrence.
- If Fault 3.1 returns, the shutter mechanism needs inspection or replacement.
Power Supply Faults
Fault 4.2, Power Supply Communication
What it is: A communications time-out between the system and the High Voltage Power Supply (HVPS).
Likely causes:
- Loose or damaged communication cable to the HVPS
- Failing HVPS communication circuit
What to do:
- Turn the system off for 5 seconds, then restart.
- If the fault persists, the HVPS needs technician servicing.
Fault 5.1, Power Supply Tolerance
What it is: An HVPS tolerance fault: the power supply output is outside expected range.
Likely causes:
- HVPS component degradation
- Capacitor bank or related circuit issue
What to do:
- Turn the system off for 5 seconds, then restart.
- If the fault persists, the power supply needs technical evaluation.
Error 14.1 / 14.2, Power Supply
What it is: A real problem with the power supply, typically a charge time-out or tolerance fault.
Likely causes:
- HVPS hardware failure
- Charge circuit fault
What to do:
- A certified technician needs to test the HVPS directly. This is not resolvable by restart alone.
- Replacement of the power supply is common at this stage.
Error 15.1, Power Issue
What it is: A general power-related fault with multiple possible underlying causes.
Likely causes:
- Power supply irregularity
- Wiring or connection fault elsewhere in the power path
What to do:
- Diagnosis by a laser repair technician is required to isolate the source.
- Do not continue operating the system through a persistent 15.1 fault.
Calibration Faults
Error 6.1, Calibration Issue
What it is: The system fails to calibrate correctly.
Likely causes:
- Dirty or damaged optical windows or lenses
- Laser head misalignment
- Worn components or fluid system issues
- Flash lamp failure (most common root cause)
What to do:
- Inspect and clean accessible optical windows/lenses if visibly dirty.
- If cleaning doesn't resolve it, the flash lamp is the most common culprit and should be checked first.
- If the fault persists after lamp replacement, escalate to an experienced laser repair technician for alignment and fluid system inspection.
Shop flash lamps and optical components →
Fault 6.2, Calibration Fault
What it is: The laser failed to calibrate to the desired fluence within 20 pulses.
Likely causes:
- Same root causes as Error 6.1: dirty optics, misalignment, lamp wear
What to do:
- Treat alongside any 6.1 fault using the same diagnostic steps: optics, lamp, alignment.
- If isolated without a 6.1 fault present, still start with optics inspection before escalating.
Shop flash lamps and optical components →
When to Call a Technician
Power cycling resolves some faults, particularly 2.1, 2.2, and 3.1, on first occurrence. If a fault code returns after a restart, or you're seeing a power supply (4.x, 5.x, 14.x, 15.x) or calibration (6.x) fault, professional diagnosis is the next step. Continuing to operate the system through a persistent fault risks further damage to the power supply or optical components.
PhotonX manufactures replacement parts for Candela GentleMax and GentleMax Pro systems. Get in touch with our team for help sourcing the right part for your fault code.