HMI Troubleshooting

Having issues with your Arri or K5600 HMI? Let's take a look at some of the steps you can do to troubleshoot the problem and get back to work quickly:

HMI Triage By Issue

Im not getting Power from the Wall

Meter the Incoming Power

On a meter, you should get 105v-125 volts at the point you plug in the ballast. If you have a circuit tester, the circuit should match your Circuit tester's CORRECT and GROUNDED light pattern (usually 2-lights On, 1-light Off) 

Check if any other electrical equipment is on the same circuit

If other electrical equipment is sharing the circuit, then you might not have enough available amperage to run the lamp you are trying to run. 

Check the quality of the outlet receptacle

Check to see how modern the outlet receptacle is. Is it old and loose in its supports? Are there burn marks on the surface or signs of melting? All of these indicators mean that you should try to use a different outlet or run power from a different room or a different source. 

Check your Cable Length / Line Loss

Over a long-distance, you can lose power due to the resistance of the copper in the cable. Ideally, you want your cable run between the power source and the ballast to be 100' or less from the power supply.  If you are over 100', you may have issues getting a unit to run at full output. If you can't make the cable run shorter, then try dimming down your ballast (on the ballast itself) to lower the wattage pull on the circuit. 

Also, between the Ballast and Lamp head, there is a limit to the number of header cables you can connect. Arri ballasts cover header cables are 150' or less, Joker ballast header cables are 50' or less. 

Wall Circuit Keeps Tripping

Check the lamp's wattage and the circuit capacity

Identify the wattage of the light you're trying to use and compare that draw to the availability left on the circuit. While most household circuits are either 20A, that's not always the case, especially in older houses. If you've done the math and you're exactly within these margins but your HMI won't stay lit, you may not have enough of a buffer between the load you're applying to the circuit and its max capacity. EX) Using an Arri 1800W M18, an Arri 150W, and a household lamp on a 20A circuit. Technically these may add up to exactly 2000W, but slight fluctuations in the draw of power can end up tripping the circuit. 

Tip! If you're in a 15A circuit house, the best place to find a 20A circuit is in the Bathroom or in the Kitchen by the counters. Try those first! 

Check if any other electrical equipment is on the same circuit

If other electrical equipment is sharing the circuit, then you might not have enough available wattage to run the lamp you are trying to run. 

Re-route power

If the circuit continues to trip, try re-routing power to an outlet on a different circuit. When striking an HMI, power surges through the unit before slowly stabilizing. Sometimes a circuit for whatever reason can't handle that surge while the light is coming up to temperature even if technically within the margins of the available power. 

Tip! If you're in a 15A circuit house, the best place to find a 20A circuit is in the Bathroom or in the Kitchen by the counters. Try those first! 

The Ballast Interface Wont Light Up

Is the fuse blown? 

All ballasts have a fuse somewhere on the unit. Remove the cap covering the fuse, take the fuse out, and check that the fuse has continuity (the wire inside should be unbroken.   

What type of ballast are you using?

A ballast that is not lighting up or responding when plugged in may be indicative of different problems depending on the type of ballast it is. If it's a more "intelligent" ballast like an Arri 1200/1800W High Speed Ballast, then failure to light up or respond could indicate inconsistent power. High-power HMI's rely on computerized, electronic ballasts to sense the quality and consistency of the flow of electricity. It may not light up at all if there are issues of this type even if other electronics will work on the circuit. Try plugging it into a more reliable circuit and see if it responds.

We see this issue most often when customers attempt to run electronic ballasts on off-brand generators, generators without enough of a margin between the draw and available wattage, and in old buildings with antiquated wiring.

For less "intelligent" ballasts (Joker 400/800, old magnetic HMI ballasts, LED ballasts) a failure to light up or respond is more indicative of a hardware or power malfunction. These ballasts are typically less picky about the quality of the power and also run at a lower wattage, so failure to turn on typically indicates something is actually broken. 

The Lamp DOES Sound like Striking, and No Light

Look for a Separate power switch on the lamp head and see if it's turned on. 

Sometimes that little switch gets overlooked. This issue happens most frequently with Arri HMI's. (K5600 Joker units do not have a switch at the lamp head)

Check Your Connections, Cable Quality, and the Bulb

If you hear the striking sound (a brief buzz or click) but don't see the bulb illuminate and start coming up to temperature, it means the conditions for striking were adequate until they were interrupted somehow. Make sure the header cables are securely fastened to one another and the plug firmly plugged into the outlet.

Look for any unnatural bends, kinks, or cuts in the cabling that may interrupt the flow of electricity. Power down the ballast and unplug the head from the header cable. Then, check that the bulb is firmly seated and free of damage/impurities. Replace the bulb if necessary. 

If the light has safety glass between you and the bulb, make sure the glass is firmly latched before operation. Some HMI's have a protective panel of UV glass that must fully depress a small brass pin micro-switch on the face of the lamp in order to strike. It's possible to hear this sound but not see light if the pin is only partially pressed. It's good practice to power down the ballast and disconnect the header cables from the lamp head before making these adjustments for everyone's safety.

Try Connecting the Lamp Directly to the Ballast

A quick way to isolate header cable issues is to remove the header and plug the lamp head straight into the ballast and attempt to strike it. If the lamp strikes successfully, then that means the header was the weak link in the chain and should be replaced. 

Important Note: You must wait for the lamp to come up to speed before turning the lamp off, or you risk damaging the bulb in the lamp. 

Test on a different circuit

If all else fails and you've traced a solid connection from the outlet to the bulb of the lamp, there may be an issue with the circuit itself. See if you can get the light working from a different power source.

The Lamp DOESNT Sound Like Striking, and No Light

Check that you are powering-on the lamp in the correct order: 

    • First, turn on the power switch on the lamp head
    • Second, connect the header cable to the ballast and head
    • Third, turn on the circuit breaker on the ballast
    • Fourth, Strike the ballast and listen for the striking sound

Check your connections and on/off switches

As you would with any problem getting a light to work, trace a solid connection from wall power, to ballast, to header cable, to lamp head and bulb. Verify everything is connected properly and powered on. Some lamps have an on/off switch or breaker on the ballast and lamp head, make sure both are engaged. 

Isolate the problem component 

Attempt to isolate where in the chain the problem lies. If everything is connected properly, is there any power coming from the wall at all? Are you getting power at the ballast but not the lamp head? This may indicate a non-functional header cable. Try swapping it with a spare. Are you getting power all the way to the lamp head but not seeing it strike? Power down and check the bulb for damage. If the lamp head has a panel of safety glass between you and the bulb, make sure it's fully latched and the brass pin fully depressed. HMI's that have UV glass will not strike unless that hinged glass panel is shut. 

Flicker/Frequency

Has the Lamp had Time to Warm Up? 

When HMI's are first turned on, they can take up to 5 minutes to come up to speed, temperature, and frequency. Give your lamp some time to make sure it's working at its best output. Patience, young master. Tell your DP to go get another cup of coffee if you need to stall for a minute. 

Shooting in Flicker-Free Mode

Check that the dial on the front of the HMI ballast is switched to Flicker-Free Mode if that option is available. This should exist on most Arri-brand Electronic Ballasts, but may not be present on all K5600, Desisti, or Power Gems ballasts. 

If the lamp is buzzing in Flicker-free mode, then you can also change the frequency dial to 60hz mode if you are shooting regular-speed (24fps). 

Rolling Effects or Pulsating

It's possible that the frequency dial on the HMI ballast is set to the wrong setting, or that the camera is shooting a non-standard frequency.

If you're working on a generator, it's possible that you're at-or-beyond the maximum output of your generator. Consider if a larger generator may be necessary, or line loss might be an issue (See Wall Circuit Keeps Tripping section, above)

Bulb End-Of-Life

This could also be a bad bulb. In very-limited instances, HMI bulb end-of-life failures may show pulsating output. Try changing the bulb to the spare and see if that helps. (Important: ALWAYS return the original bulb AND the spare bulb to the rental house to avoid being charged a replacement fee!) 

If you have to replace the in-lamp bulb with the spare bulb, once again check for any chips or breaks in the base and ensure it is properly seated within the lamp head. After replacing the bulb you should wipe the new bulb down with an alcohol pad before striking to remove any oils or impurities from its surface. Wiping the bulb down will make sure there are no dust or particles left on it that can potentially burn within the lamp head. Whenever replacing bulbs, refrain from touching the glass with your bare hands, any residue left on the glass may cause the bulb to break or deform once heated. Grab the bulb from its porcelain base with a clean paper towel or cloth only once cooled.

Color Shift Issues (Magenta/Green)

Let it settle

One of the most noticeable causes of color shifting within the lamp is the striking process itself. HMI’s won’t be at their full light output immediately after powering on, it takes a few moments for the lamp to warm up and stabilize in color and intensity. The light will shift color until it reaches maximum intensity, at which point the color temperature should settle into its expected range.   

Adjust the knobs

If the light has fully warmed up and you’re still noticing color shifting issues, ensure the dimmer on the ballast (if applicable) is turned all the way up. If the lamp is dimmed down it may cause some slight color shifting. Try adjusting the spot and flood, as the bulb changes distance from the lens of the lamp there may also be slight variations in color.

Dimming in the Ballast Can Cause Color Shift

If you have dimmed the ballast, consider bringing the dimmer back to max power, and use metal scrims instead to lower the output. HMI bulbs sometimes produce purple/green shifts when they are dimmed. 

It Might be the Lamp Head's Natural Color

Different generations of HMI's and bulbs have different native colors. Sometimes small shifts in color can be natural, and it's not an issue. A good way to ensure matching color temperature in the future is to require matching fixtures from the rental house and do a checkout. During the checkout,  run both fixtures against a color meter. In this case, the best way to correct the color is to use Color Correction Gels on the front of the lamp.  

Power Supply

Similar to how the lamp shifts color while it's warming up, it may also shift color if it is not getting an adequate amount of power. Ensure the lamp is on a working circuit and that there is enough headway between the wattage of your lamp and the amperage of your circuit. 

The Bulb is Reaching End of Life

Now is a good time to switch to the spare bulb. If you have to replace the in-lamp bulb with the spare bulb, once again check for any chips or breaks in the base and ensure it is properly seated within the lamp head. After replacing the bulb you should wipe the new bulb down with an alcohol pad before striking to remove any oils or impurities from its surface. Wiping the bulb down will make sure there are no dust or particles left on it that can potentially burn within the lamp head. Whenever replacing bulbs, refrain from touching the glass with your bare hands, any residue left on the glass may cause the bulb to break or deform once heated. Grab the bulb from its porcelain base with a clean paper towel or cloth only once cooled.

Smells like Burning or Melting

Ensure Safety

The priority should be making sure nothing has caught fire and that the set remains safe. Assess the severity of the smell, immediately strike down the offending lamp if it can be identified. Flip the ballast breaker into the off position (if applicable) and unplug before investigating further. Depending on the source of the burning or melting, it's possible that electrical wiring has been exposed or other hazards created by the live flow of electricity, so it's good practice to completely disconnect the lamp until the issue can be diagnosed.

Check to make sure the power cable you are using is adequate to support the lamp you are using. 

Checking the wattage of your light, the capacity of the circuit you want to run it on, and the overall quality of the power source is also important. Check that your power cables are 12 gauge for all HMI's under 1800w. In limited circumstances, HMI's under 800w can be run on a 14 gauge cable, but not anything smaller than that. Do not run multiple 800 HMI's on a 14 gauge cable (step up to 12 gauge) 

Common Sources of Burning/Melting

The most common cause for a burning scent is a flag, fabric, gel/diffusion or other object that is positioned too close to the beam of a lamp. Tungsten and HMI's create a lot of heat when in operation, and it's important to leave enough space and ventilation between the light and any modifiers that aren't specifically rated for high heat usage. Indirectly using your hand to feel how far from the lamp head the heat travels, and occasionally checking on the light during operation is a good method for preventing damage. If holding your hand in the beam is too hot to withstand indefinitely, it is likely too hot for anything else to be that distance as well.

A more innocuous source of a minor burning smell can come from dust that has collected in the lamp head or lens. Dust will usually burn away in about a minute, sometimes with a small wisp of smoke, but it's important to monitor the lamp until it completely stops. If the smoke worsens/accelerates, something else may be wrong.

Dead Bugs

Less common, but more severe sources of burning include bugs or other debris that have become lodged in the lamphead (usually from shooting in the woods at night), malfunctioning electronics somewhere in the lamp, ballast, or header cable, or electrical hazards with the house power of your location. Making sure that the reflector, lens, header cable pins/ports, and cable connections are all clean, free of debris, and dry are crucial to the safe operation of your light.

Building Issues

If you continue to smell burning after powering off your lights, the problem could be a much more severe issue with the location itself (fire, overloaded circuit with non-functioning breaker, etc.) and you should consider calling emergency services or halting production until safety can be guaranteed. This would be a time to call a certified building electrician or superintendent to inspect the electrical situation. 

I See Sparks, Exposed Wiring, Melted Cables, Burn Marks

Immediately power down, unplug, and label the lamp clearly as Non-Functional with tape or signage, and refrain from using the lamp. Issues of this magnitude probably can't be remedied on set. Contact Lightbulb's Emergency Service line if our immediate attention is required.       

Bulb Issues

Make sure the bulb is properly seated

A good indication for a potentially unseated bulb is the buzz/click sound made by the unit trying to strike without any light being produced, or simply no reaction from the lamp at all.

Check the bulb for damage

If the bulb is properly seated and the pins are fully engaged, check to see if there is any cosmetic damage to the bulb itself. The bulb will fail to strike if there are any chips or breaks in the porcelain base of the bulb. Residue buildup/corrosion within the arc points of the bulb may also cause a failed strike. 

Switch to the spare bulb

If you have to replace the in-lamp bulb with the spare bulb, once again check for any chips or breaks in the base and ensure it is properly seated within the lamp head. After replacing the bulb you should wipe the new bulb down with an alcohol pad before striking to remove any oils or impurities from its surface. Wiping the bulb down will make sure there are no dust or particles left on it that can potentially burn within the lamp head. Whenever replacing bulbs, refrain from touching the glass with your bare hands, any residue left on the glass may cause the bulb to break or deform once heated. Grab the bulb from its porcelain base with a clean paper towel or cloth only once cooled.

HMI Triage by Lamp Section

Wall Power Issues

Meter the Incoming Power

On a meter, you should get 105v-125v at the point you plug in the ballast. If you have a circuit tester, the circuit should match your Circuit tester's CORRECT and GROUNDED light pattern (usually 2-lights On, 1-light Off) 

Check if any other electrical equipment is on the same circuit

If other electrical equipment is sharing the circuit, then you might not have enough available amperage to run the lamp you are trying to run. 

Check the quality of the outlet receptacle

Check to see how modern the outlet receptacle is. Is it old and loose in its supports? Are there burn marks on the surface or signs of melting? All of these indicators mean that you should try to use a different outlet or run power from a different room or a different source. 

Check your Cable Length / Line Loss

Over a long-distance, you can lose power due to the resistance of the copper in the cable. Ideally, you want your cable run between the power source and the ballast to be 100' or less from the power supply.  If you are over 100', you may have issues getting a unit to run at full output. If you can't make the cable run shorter, then try dimming down your ballast (on the ballast itself) to lower the wattage pull on the circuit. 

Also, between the Ballast and Lamp head, there is a limit to the number of header cables you can connect. Arri ballasts cover header cables are 150' or less, Joker ballast header cables are 50' or less. 

Ballast Issues

The Strike Button on My Ballast Isn't Causing the Lamp to Strike. 

First thing to check is if the fuse and circuit breaker are good on your ballast. Check the fuse by unplugging the ballast, opening the fuse cap on the ballast, and then checking the continuity of the fuse with a meter. If the fuse is good, then check that the Circuit breaker is in the ON position before attempting to strike again. 

My Electronic Ballast Won't Work on Some Outlets

High-power HMI's rely on computerized, electronic ballasts to sense the quality and consistency of the flow of electricity. It may not turn on at all if there are issues of this type even if other electronics will work on the circuit. In sensing a power or grounding issue, the ballast may refuse to respond at all as a way of protecting the complex inner-workings of the unit. Attempt to locate an alternate circuit or source of power. 

My Ballast Works On Wall power, But Not on a Generator

The answer above also applies to generators. Depending on the type of ballast and generator in question, you may or may not get the ballast to turn on. If it turns on but will not strike your lamp, it could either be attributed to issues already outlined or because there isn't enough headroom between the draw of the HMI and the wattage available via the generator. EX) an Arri 1800W M18 will likely not strike on a Honda 2k Putt Putt generator. The ballast will likely sense grounding issues AND the 200W headroom is not enough to strike and sustain the HMI. It would be more appropriately paired with a Honda 3k Generator or larger for both reasons. 

Squealing Sound Coming from Ballast

HMI ballasts can sometimes emit a high pitched squealing sound, typically loudest immediately after striking. It'll usually taper off into silence or a much quieter hum. You can sometimes adjust the pitch/volume of the noise by adjusting the frequency knob on the ballast (if applicable) to a specific frequency instead of Flicker Free. It's normal for this to happen and is rarely an issue, consider running a longer header cable and locating the ballast farther from the action if it interferes with sound recording.

Header Cable Issues

I'm Getting Power to the Ballast, But Not The Lamp Head

If the power source is a reliable, working circuit, you may have isolated the issue as a non-functional header cable. If you have a spare, try swapping it out with a new one. 

Depending on where the ballast and lamp head are located, sometimes it can be easy to isolate header cable issues by plugging the lamp directly into the ballast and attempting to strike the lamp. If the lamp strikes happily, then that quickly tells you it's a bad header cable. 

I See Sparks, Exposed Wiring, Melted Cables, Burn Marks

Immediately power down, unplug, label clearly as non-functional with tape or signage, and refrain from using. Contact Lightbulb's Emergency Service line if our immediate attention is required.     

Bent Header Cable Pins, Dirt in Ports/Pins

For safe, reliable usage of an HMI, the power connections must be free of debris, clean, and dry. The pins on the male end of the cable must be aligned properly and the female ports unobstructed. Misalignment of the pins or header cables improperly screwed together may be dangerous to you and the unit. If dirt makes its way into the header cable, you may experience smoking or other hazardous effects. We may be able to provide instructions to remedy the problem on-set and avoid further damage or provide you a replacement component. 

Lamp Head Issues

Lamphead is Not Getting Power But The Ballast Is

Some HMI's have an on/off switch on the lamp head itself as well as the ballast. Make sure both are engaged in the ON position. If the ballast is receiving power and the header cable is functional, the lamp head should be responsive if powered on. 

Lamphead Receives Power but Won't Strike

Check that the bulb is in good condition and properly seated in the lamp head. If the light has safety glass between you and the bulb, make sure the glass is firmly latched before operation. Some HMI's have a protective panel of UV glass that must fully depress a small brass pin and microswitch on the face of the lamp in order to strike. It's good practice to power down the lamp and disconnect header cable connections before making these adjustments so that no one is staring directly into a light that may strike once corrected.

I Had to Adjust the Bulb and Now I Can't Get it to Lock in Place

On an Arri AS18/M18 and some 1200W units, there is a bulb latch on one side of the lamp that when turned, can release or secure the bulb. If this latch is improperly forced in the wrong direction or receives impact damage, it may loosen and be unable to tighten enough to lock. This is a fixable issue, but involves repair bench service. It's not advisable to make these repairs yourself in the field, please contact us and we will help figure out a solution.

We're Shooting Outside and Now our HMI is Filled with Dead Bugs

Gross. But it happens, especially on-location outside of the city. Remove the bulb and do your best to carefully remove the bugs that you can with a vacuum cleaner nozzle, a medium percentage or diluted isopropyl alcohol, and a soft fabric or paper towel. It's important to keep your lights clean and properly ventilated, but the surfaces and inner-workings of an HMI are delicate. Allowing dead bugs to remain in the hot lamp could permanently damage the reflector, but so will scrubbing the lamp with harsh chemicals and abrasive sponges. Do not scrape at or scratch the reflector surface or chip paint away from the lamp-head. Contact us for advice on proceeding and minimizing billable damage. 

Bulb Issues

Save and return dead bulbs

If a bulb naturally burns out or fails, you will not be charged for the damage. Charges may apply if a bulb was broken. We cannot verify what happened to a bulb that is thrown away on-set and may have to bill your production if BOTH the in-head AND spare bulbs are not returned

Make sure the bulb is properly seated

A good indication for a potentially unseated bulb is the buzz/click sound made by the unit trying to strike without any light being produced, or simply no reaction from the lamp at all.

Check the bulb for damage

If the bulb is properly seated and the pins are fully engaged, check to see if there is any cosmetic damage to the bulb itself. The bulb will fail to strike if there are any chips or breaks in the porcelain base of the bulb. Residue buildup/corrosion within the arc points of the bulb may also cause a failed strike. 

 

Switch to the spare bulb

If you have to replace the in-lamp bulb with the spare bulb, once again check for any chips or breaks in the base and ensure it is properly seated within the lamp head. If the bulb has a "nipple", a small glass protrusion designed for heat dispersion, please make sure it is facing upwards when installed. After replacing the bulb you should wipe the new bulb down with an alcohol pad before striking to remove any oils or impurities from its surface. Wiping the bulb down will make sure there are no dust or particles left on it that can potentially burn within the lamp head. Whenever replacing bulbs, refrain from touching the glass with your bare hands, any residue left on the glass may cause the bulb to break or deform once heated. Grab the bulb from its porcelain base with a clean paper towel or cloth only once cooled and return to us any dead bulbs from your order. 

EMERGENCY SERVICE

Lightbulb Grip has a 100% Rain-or-Shine Service Guarantee

If you've tried the steps above and are still having issues, call our emergency phone line and receive immediate support: