SunSpot 2: Troubleshooting, every question, answered
43 answers below, written from the manufacturer's manuals and our own bench experience. Prefer to tap through them? The same answers power the live chat in the corner. Ready to buy? See the SunSpot 2 or request a quote.
Low output, is tip distance the cause?
If the guide tip sits too far from the substrate, intensity falls off fast. Bring it to within 1/2 to 3 inches of the surface, balancing the spot size and intensity your process needs.
Low output, intensity set too low?
Check the front panel intensity control and raise it toward 100%. Also confirm the light guide is pushed fully into the receptacle, since partial insertion deliberately trims output.
Adhesive won't cure, wrong spectrum?
Compare your adhesive's spectral requirements against the lamp and filter charts in the manual's specifications section. If they don't overlap well, options include an optional lamp type such as the UVB-enhanced UV2170, or removing the heat filter for short-wavelength work, ask us before changing the optical stack.
Weak output after a lamp change, why?
Usually a focus problem: the reflector rim isn't centered and fully seated in the mounting extrusion's circular positioning groove, or the light guide isn't fully inserted in the front receptacle. Re-seat each per the maintenance section and re-test.
Could dirty optics cause weak output?
Absolutely, the lamp reflector, in-line heat filter, and light guide all collect dust and condensed vapors. Inspect each and clean with isopropyl alcohol (or replace if damaged) following the section 7 maintenance procedures.
Output faded gradually, is the lamp done?
Gradual decline is the standard aging characteristic of all arc lamps: output typically falls to 50% of new by around 2,000 hours. Check the hour meter, and if the lamp is defective or excessively aged, replace it per the maintenance section.
Lamp won't light but fans run, first check?
Hot-strike protection is the most common cause, a hot lamp cannot re-ignite. Leave the unit running and the lamp will restart on its own within 2 to 5 minutes, once it's cool enough.
Could over-temp protection stop the lamp?
Yes, if the unit overheats, over-temperature protection keeps the lamp off. Allow the unit to cool, clean the fan filters, and consider a cooler operating environment or better rear-panel airflow clearance.
Lamp not lighting after maintenance?
Verify the lamp is properly installed: reflector rim seated in its circular groove, the reflector wire centered in the top notch, and the lamp's electrical connector fully depressed into its receptacle on the center divider.
Lamp off with PLC wiring connected?
Check pin 5 of the rear DSUB connector, a low Lamp Off signal commands the lamp off. Correct the external signal (or disconnect the interface cable) and the lamp can ignite normally.
Lamp still won't ignite, is it dead?
If hot-strike, over-temperature, installation, the ignition retry timer, and rear-panel signals all check out, a defective or excessively aged lamp is the remaining cause. Replace it per the maintenance section and log the new baseline.
Unit is completely dead, power cord?
When the lamp, fans, and hour meter are all off, first verify each end of the power cord is fully inserted into its socket. Replace the cord if it's defective, UV0341 is the US version.
Unit dead, is the outlet live?
Test the wall outlet for power. Also confirm the outlet's voltage matches your unit, 120 VAC for the UV1853 model or 240 VAC for the UV2132.
No power, could the access panel be why?
Yes, the lamp access panel safety interlock cuts all input power if the side panel is removed or not fully closed. Make sure the panel is seated, its three thumbscrews are tightened, and it's contacting the interlock switch.
How do I check or replace the fuse?
With the unit off and unplugged, check the AC input fuse on the rear panel; if blown, replace only with the same type, time-lag 6.3 A, 250 VAC, 5.2 x 20 mm glass (UV2136). Also verify the lamp is properly installed and the AC input voltage is in the appropriate range for your model.
Shutter won't open, most common cause?
The light guide safety interlock. The shutter will not open unless a guide is installed and seated deep enough in the front receptacle, push it in until the locking spring clicks.
Shutter won't open right after power-up?
The shutter stays closed until the lamp finishes warming up. Wait about 2 minutes for the Lamp Ready indicator to light, then try again.
Pedal press does nothing, connector issue?
Verify the foot pedal (or interface cable) is fully seated on the rear DSUB connector and its locking screws are fully tightened. A loose connector is one of the four listed causes for a shutter that won't open.
Shutter won't open under PLC control?
Check the signal at pin 1 of the rear DSUB, the shutter-open input is active low and must meet the TTL levels (high 2.0 V or more, low 0.8 V or less, 5.0 V max). Compare your output module against the wiring diagram in manual section 2.4.
Unit shut itself off mid-shift, why?
Internal over-temperature shutdown trips at 65 °C. Let the unit cool, wash the fan filters, confirm 12 inches of rear clearance for airflow, and keep the ambient at or below the +40 °C operating limit.
One splitter leg cures slower, fix?
Measure each leg with a radiometer, rotate the guide handle in 30-degree increments, and re-measure until the legs balance to within about 10%, then lock the handle thumbscrew. Also inspect the slow leg's output tip for cured adhesive or contamination.
Cure spot is the wrong size?
Adjust the tip-to-part distance within the 1/2 to 3 inch working range, closer is smaller and more intense, farther is wider and gentler. For finer control, a different guide diameter or configured focusing optics will dial it in, ask us.
Parts run too hot during curing?
Confirm the in-line heat filter is installed, together with the dichroic reflector it removes nearly all the heat-producing energy. Then try more tip distance or a lower intensity with a correspondingly longer exposure, and always cure on a metallic or non-flammable surface.
What causes sudden early lamp failure?
The two big ones are interrupting the warm-up ramp, which can even lead to non-passive failure, and skin oils on the glass, which create localized hot spots on the quartz envelope. Let every warm-up finish, and handle lamps only with clean gloves or a soft cloth.
Output dropped after moving the unit?
A dustier location clogs fan filters and coats the lamp, reflector, heat filter, and guide tip, all of which attenuate UV. Clean the fan filters and optics per manual section 7 and re-check output; relocate to a cleaner area if it keeps recurring.
Ready LED never lights, what now?
First confirm the lamp actually ignited, the Lamp On indicator glows bluish when it's lit. If the lamp is on, give it the full 1-2 minute warm-up; if it never ignites, work the lamp-not-lighting checks (hot strike, over-temperature, installation, ignition timer), and contact us if it still won't come up.
Cure times keep drifting longer?
Slow drift points to consumables: lamp output decays over its 2,000-hour life, optics collect contamination, and liquid guides lose transmission over one to two years. Compare radiometer readings against your logged baseline to see which one has moved.
How can a radiometer help troubleshoot?
It separates causes: measure at the guide tip and compare with your as-new baseline. A low reading with a fresh lamp implicates the guide or filters; a reading that recovers after a lamp swap confirms lamp aging; a normal reading shifts attention to exposure time, distance, or the adhesive itself.
Where's the full troubleshooting table?
Section 8 of the SunSpot 2 manual (pages 25-26) lists every symptom with probable causes and solutions, low output, lamp won't light, no power, and shutter faults.
Tried everything and still stuck?
Contact us, describe the symptom, what you've already checked, and the lamp hours, and we'll help isolate it. If the fault is beyond user maintenance, we'll arrange factory service with Uvitron and the RMA paperwork.
What fault protection is built in?
The power supply protects against inrush current, line voltage surges, short circuit, open circuit, hot re-strike, and over-temperature, plus a 3-minute ignition retry timeout. Most apparent faults are these protections doing their job, check the troubleshooting table before assuming hardware failure.
Hour meter runs but lamp stays dark?
That combination means input power is good and the fault is in ignition. In order, check: hot-strike protection (wait 2-5 minutes), over-temperature protection, lamp installation and connector, the 3-minute ignition retry timeout, a Lamp Off signal at rear pin 5, and finally lamp end-of-life.
Can wrong supply voltage damage the unit?
Yes, each system is factory configured for 120 VAC (UV1853) or 240 VAC (UV2132), and connecting to the wrong input voltage can cause malfunction and possibly permanent damage. Check the model number before plugging into a new circuit.
Skin turned red after working near it, why?
That's UV erythema, even limited UV exposure reddens normal skin, and a few seconds of direct radiation can equal a day in the sun. Treat it as a sign your shielding or work habits need attention: wear protective clothing and cotton gloves, and review the enclosure before continuing.
Eyes feel gritty after UV exposure?
UV eye burn isn't felt for several hours, then feels like sand in the eyes that can't be washed out, identical to welder's burn, and it takes days to heal. Have it checked by a medical professional, and make sure everyone in the area wears 5.0-shade UV/IR eyewear from now on; some UV effects on eyes can be permanent.
Lamp has become hard to start, why?
Lamps that were repeatedly shut off during their warm-up ramp become hard or impossible to start, and ordinary aging has a similar effect. If power-cycling to reset the ignition timer and a full cool-down don't help, replace the lamp.
Lamp is lit but nothing exits the guide?
The shutter isn't opening. Run the four checks from the troubleshooting table: light guide fully seated (interlock), warm-up complete (Ready lit), pedal/DSUB connector tight, and, if externally wired, the shutter signal at pin 1.
Does the fuse protect the lamp too?
Yes, the rear AC input fuse protects the power supply and the lamp, which is why it must be replaced only with the same rating: time-lag 6.3 A, 250 VAC.
Fuse blew again after replacement?
Re-verify the basics from the troubleshooting table: correct fuse type (time-lag 6.3 A), lamp properly installed, and AC input voltage within range for your model. If it keeps blowing, stop and contact us, we'll arrange factory service rather than have you dig into the electrical system.
Whom do I contact for technical help?
Start with our tech support page, we're a US-based supplier and respond within one business day. For anything needing factory work, we coordinate service and RMAs with Uvitron International, the manufacturer.
My unit was dropped, can it be repaired?
Have it checked before putting it back into service, accident damage isn't covered by the warranty, but factory repair is available for a fee based on the degree of repair. Contact us and we'll arrange the service and RMA.
Can I bypass an interlock to keep working?
No, the interlocks are what keep UV radiation and high voltage contained, and defeating them risks eye and skin burns or electrical shock. Fix the underlying cause instead: seat the light guide fully, or close the lamp access panel so it contacts the interlock switch.
Where can I get the SunSpot 2 manual?
Right here, the complete 31-page instruction manual (Rev D) covers installation, operation, maintenance, the full troubleshooting table, and the replacement parts list.
