misterstrobe

The Hensel flash unit requires no special mount. The Hensel flash unit accecpts the standard 16 mm spigot found on most lighting stands. The picture you included is showing a complete assembly of flash unit and stand. If this is what you have I don't see what problem there might be in getting additional light stands. Next time you go to a shop make sure to take the blue bottom part of the mount along. This is the receptacle for the spigot.

Hans Strobl

Hello Christopher,

having had the problem some time ago I found the material perfectly suited for that purpose in a textile fabric material that is black on one side and silver on the other. Here in Europe it is made available by the flash equipment manufacturer Hensel Studiotechnik and it is sold in any desired length. It comes 1.3 m wide (about 51").

I don't know about the availability in the US, but perhaps you can talk one of their representatives into getting a piece for you. Try to contact Marc Gottula of Image Light Group, Inc. (mgottula@henselusa.com). I don't know him personally, but I heard from others that he is very attentive to the needs of photographers.

Perhaps this will help: http://www.henselusa.com/content/reflex.pdf

Hans Strobl

Hello Dennis, I couldn't resist to add my 2 cents worth to this topic.

You are asking "does anybody know if there is coming a new profoto ringflash (like the Bron)?"

Why should Profoto bring out a ring flash like the Bron? I am sure, or at least I hope that if Profoto puts a new ring flash on the market they would go the cool LED way for the modelling light. I heard this seems to be the upcoming trend at Photokina in September. Dennis, the fact that broncolor is not mentioning any limits doesn't mean that there are any and that their ring flash is detached from the physical dictates that are of concern with all ringflash constructions. Like Ellis pointed out already in a very polite way that the Bron ring flash is "basically identical in construction" I can confirm, matter of fact in the past they had the same origin. Also, it is not correct to assume that the Bron unit has more stamina than the Profoto ProRing because it has a 2 fan cooling system. The reason why the new Bron ringflash requires a cooling system is due to the heat generated by the ten 20 W halogen bulbs. By the way, who wants a ring flash unit with whining turbo fans blowing hot air next to oneﾒs head. The modelling light in ring flashes is not really a big issue here in Europe because they are mostly used in concert with other light sources possessing their own much more powerful modelling lights.

True, the 9600 J/minute rating of the ProRing will allow you to poke off only 16 shots at 600J and a 4 second interval; 32 shots on 300 J at 2 seconds interval; 64 shots at 1 second interval when the flash power setting is on 150 J. But the intervals don't have to be evenly distributed. You can shoot away in irregular fast bursts, as long as there are pauses in between and the total is not more than the maximum recommended. But I warn you: you are most likely to ruin the pack if you're taxing it too heavily. I am sure the pack goes before the Profoto ProRing does. A ring flash does not go bad and ruin a pack consequently; the pack is the weak factor. It's capacitors heat up considerably under rapid shooting. A ring flash can get hot, very hot and if it starts to smell funny you can always pause and allow it to cool down. If a pack is emitting any strange odors its already damaged or gone.

By the way, the Hensel ringflash is rated at 15.000 J/min!

IMO, if the Bron ringflash is placed in a reflector like the Para it is bound to loose its specific character and the Para will determine the lighting character instead. In this application the Bron ringflash "P" will perform just like any other source in a variable focus setup, but, I doubt that it will have the stamina of other heads designed for this specific purpose.

Also, its 200 W modelling light will not be strong enough to be easily integrated in an existing lighting setup. Practically it won't emit more light than you get from a single 100 W halogen and it will have all the disadvantages of a system based on the series connection of light bulbs (if one goes, the whole string is dead). Using the Para for fill would be a waste, as a key/main you will need somewhat more power for modelling than the puny output of ten small halogen bulbs.

Broncolor makes fine lighting gear, indeed. But I think they are galloping in the wrong direction with their ringflash "P".

Am I anxious to attend Photokina this year!

Hans Strobl

David, what little information I have on this unit comes from memory. By all means have the unit checked by a service technician. I can not be held responsible if anything goes wrong.

What the picture shows is an old Quad 8000 Link Unit of vintage 1976 which was originally intended for bundling-up 4 Quad 2000 generators/packs to supply the combined power to a single head. I can't tell by the picture which type head is actually connected now. Because I can make out a single flash tube only I am questioning its capability to handle the full flash power of all 4 generator/packs if connected to the link unit. The link unit also provides a dimming function for the modelling lamp. If I remember correctly, the 20-pin flash power jacks are providing a means to use additional heads, dividing flash power output symmetrically.

The unit shown has been modified to certain extend because originally there were 4 mains power leads (mains out to the packs) with the old, mediocre Bowens 3-pin mains plug. The link unit you have is sporting one of the old plugs which were used to power a Quad 2000 Issue 1 of 1976. The other 3 plugs must have been replaced sometime later with the standard plugs found on Bowens equipment since 1977. The old Bowens mains plug is not up to electrical standards. Stepping on it will break the hard plastic housing. Bowens discontinued this type plug in 1977. No need to ask why.

The cable in the middle with the Australian 3-pin plug seems to have been added later. This is where the mains power goes in. Originally the mains power was fed to the Bowens dedicated 3-pin jack on the lower left of the box. I believe that the modern mains jack on the lower right was also added later on.

It looks as if the flash power cable is torn out of the feed-thru insulator of the link unit. There is a lethal 640 Volts going through that cable! I hope that you are aware of the risk you are taking in using such old equipment.

Hans Strobl

Wuerzburg, Germany

Neither one has the necessary connection to drive the cooling fan of the Quadmatic 6KH head.

Therefore it will be subjected to extreme thermal strain without the cooling. I would not risk it. A new 6000 J flash tube will cost about US$ 500. However, there is no need to get a Quadmatic generator, although it would be advisable because of the built-in modelling lamp dimming circuit. The Quad 2002 can be modified to run the fan in a Quadmatic head by having a wire bridge installed in a certain place on the flash power jacks. This is NOT a DIY job. Turn the combo in to a Bowens service station.

"We had the meter hooked up from the mains to the pack. Could it be sending a charge back thru to the mains? "

Dave, it is not possible for the unit to send a charge back to the mains electrically. The system strictly works one way. Hooking-up a meter to the pack will not get you much useful information. A technician would have to use an oscilloscope with memory function set on one-shot mode.

Generally speaking, all well-designed flash units will incorporate a so-called glow prevention circuit which cuts-off the charging circuit from the mains for a fraction of a second after firing a flash. This short delay (about 0.3 s) will prevent the hot plasma in the flash tube to continue glowing, being fed by the mains (after-glow prevention). The charging circuit of your Bowens Quad 2000/2002 will be dead for this short time. When starting the charging cycle the unit will be drawing about 25A peak (start of cycle), coming down to about 6A average for the remainder of the cycle. Once the ready indicator light comes on, the current is about 1A.

What you have to worry about are other things:

1.the Quad 2000/2002 does not have any efficient EMI filtering, meaning there is considerable interference being fed down the mains line. This may have negative effects on all electronic devices e.g. radios, computers, transceivers etc.

2.the sync voltage is 200 to 250 VDC, which is asking for trouble when using modern cameras. Wireless trigger devices are not necessarily a solution to the problem, their circuitry is affected the same way. E.g. Bowens Pulsars are 25 VDC max.

One last word of caution:

If you do not have the proper qualifications in electrical work -- do not attempt doing repairs yourself. Repair of flash equipment is hazardous work and can be fatal when electric shock occurs.

Your father, though being an electrical engineer, still has to familiarize himself with the specifics of flash equipment. Make him aware that the power capacitors of the Bowens Quad 2000/2002 are charged to 640 VDC, so proper safety precautions must be taken.

If he has any questions pertaining to the design of the Quad, have him contact me.

Hans Strobl

Wuerzburg,

Germany

Hello David, seeing you have not had any response so far makes me cut in at this point, although I am not in possession of the manuals or schematics.

The Bowens Quad 2000 pack is of vintage 1974, being followed by the Quad 2002 in 1978. One important thing to know is that you have to switch off the mains power and wait about 3 seconds before unplugging or changing heads. Both units have a sync voltage on the jacks of about 230 VDC. By all means, do invest in a safe sync device. This applies not only when you intent to trigger via sync cable, this advice is also valid and good when using one of the popular radio remote gadgets. I remember the time when Bowens introduced their first issue infrared wireless remote in 1981 and were forced to make an alteration in the electronic circuitry a year later when damages occurred due to the high sync voltages of the old packs.

The flash power jacks of the Quad 2000 and Quad 2002 packs are lacking the extra hot wire connection to supply power to a cooling fan (original heads are without a fan), therefore it is best to limit the modelling light for the halogen type heads Quadmatic H/K to 300 W max. The older Quad heads take an E 27 socket 250/275 W tungsten bulb.

The problem you have with No.2 section one of the Quad 2002 indicates that the flash power capacitors of that particular section are going bad. Having them replaced with new ones would run about $150. Marking No.2 switch accordingly and leaving it off permanently would still get you a usable unit of 1100 Joule. You may have noticed, on the Quad 2000/2002 all sections that are switched on must show the section ready indicator before the central ready indicator comes on. The ready indicator will come on already when 70% of full charge is reached, making it possible to trigger the unit this soon. Flash power is not stabilized, but after about 6 seconds charging time the units are fairly constant in output. Triggering the units immediatly after the ready indicator comes on will yield uneven exposures.

The available flash power is applied symmetrically to the flash power jacks on the Quad 2002.

You may switch a section off in order to reduce flash power, even when all are in ready condition. An internal power dump discharges the switched sections in about a second.

All this is from memory. Perhaps there are others who are still in possession of manuals.

Hope this helps,

Hans Strobl,

Wuerzburg, Germany

Mark, the Bogen Mono 4000/9000 units were manufactured by Bowens from 1983-1989. Searching the web may yield better results hunting for the equivalent model Bowens Mono 200D (Mono 4000) and going for the Bowens Mono Bronze, Mono Silver, Bronze DX, Silver DX (Mono 9000). Replacement flash tube assemblies for both models can be purchased from Calumet.

Hope this helps

Hans

Darryl, the code on the Bowens Type A capacitor says: 1200 mF Photo Flash Capacitor, 400 Working Volts Direct Current, safety vent in bottom of can, manufacturer BHC. This type capacitor is not being produced anymore. The dimension of the can is 40.5 mm in diameter and 115 mm in height. Earlier Bowens Mono 9000 came with capacitors which had the safety vent on the bottom of the can (type QVS), younger models (year of 1984) came with the types which had the vent integrated into the lid of the can (type QS).

You have 2 alternatives:

1. Have a technician take the busted capacitor out of circuit. Flash power is reduced to 2/3, but this will keep the cost of repair to a minimum. If the capacitor is dry and clean, it may remain in the capacitor compartment. If it's leaking electrolyte it must be removed. In this case a suitable spacer must take its place to keep the other capacitors firmly in position.

2. Because all flash power capacitors must be matched by their electrical characteristics, you can't just simply replace the bad one with a service capacitor, even if you would be able to find the identical type. For reliable operation all 3 capacitors of the Mono 9000 must be replaced.

The problem a service technician will encounter is in finding suitable capacitors, not only as to their electrical values, but mainly as to their physical size. The compartment in your Mono 9000 is 83 mm wide, giving a good fit to 2 cans each ca. 41 mm in diameter. Neither Duracap nor Cornell-Dubilier have service capacitors in those dimensions with the appropriate capacitances, correct me if I am wrong.

A qualified service place for Bowens flash equipment could use the Bowens Type "AC" (Siemens/EPCOS B 43415-B9218-A000) photo flash capacitors found in the Bowens/Calumet Prolite/Travelite 120 series. However, because they are only 80.8 high a spacer of 34 mm will have to be used on the bottom of the capacitor pack. The capacitance is 2100 mF each, so using 3 of them would give your Mono 9000 the power of a Mono 15000. This will be the max the flash tube can handle. Don't go for the more powerful EPCOS B 43415 B9308 A000 capacitors.

The Bowens type "F" capacitors (310 NP 250 HS BHC 8520) are part of the voltage multiplying circuit and they do not supply any power to the flash tube. They are somewhat ruggedly built, and they usually are not problematic. Their direct replacement is the Bowens type "FF" (310 NP 250 H3S) found in the Prolite/Travelite 120.

Here is a link which may prove to be helpful:

http://www.epcos.com/web/generator/Web/Sections/ProductCatalog/Capacitors/AluminumElectrolytic/Photoflash/Page,templateId=render,locale=en.html

If you have any questions, I'll be glad to help. But whatever you do, don't tinker with your Monos unless you are a trained technician experienced in handling high voltage flash equipment.

The information which I volunteer should be no invitation to anyone to execute repairs on potentially hazardous equipment such as flash units in a do-it-yourself fashion. You do, whatever you do, at your own risk.

Hans Strobl<div></div>

You will find more information here:

http://folk.uio.no/gisle/photo/gt301b.html

Peter, the Broncolor S1400 generator you bought was introduced by Bron in the year 1969. It's a workhorse and may still see a few years of service. The various flash power settings are obtained by capacitance switching, meaning you get consistent colour temperature throughout. Matter of fact, your "new" old flash unit was 20 years ahead of other brands on certain aspects.

The flash power capacitors are charged to 480 VDC with an accuracy of +- 2%, which is pretty good for a unit this age. You may be at ease knowing that the Bron S1400 has a sync voltage of less than 15 VDC, making it safe to use with most digital cameras.

If your unit should ever need repair, a competent service technician should be able to replace the power capacitors with the appropriate substitutes. The electronic circuitry is on separate PCBs using readily available non-critical components.

The flash power outlet will accept the standard 20-pin plug used by Bowens, Broncolor, Elinchrom and Hensel, but the wiring is not the same. Also, the flash power jack of the S1400 does not supply the voltage to drive a cooling fan, making it somewhat more difficult, though not impossible, to adapt other flash heads to the S1400.

I have to warn you when using the old Bron flash heads for portraits of people. They are just not considered safe anymore by current standards and you may be putting yourself out on a limb when using those heads for portraiture.

When a halogen bulb burns out the filament opens up, resulting in a strong arc-flash being fed from the mains supply, drawing a very heavy current for a short time. The excess heat thus generated may bring the already red hot quarz glass envelope to explosion. The bits of hot glass can set fabrics and paper on fire, but still worse is the possibility of harming persons (models, customers, etc.). This is the reason why manufacturers of flash equipment specify a certain type of fuse to warrant that the supply circuit is interrupted fast enough before any damage or harm is done. Just keep in mind: If the bulb goes the fuse must go too.

The old Bron heads are carrying a sticker with a recommendation for a 10 A FF fuse. Be cautious! This applies only to a 650 Watt halogen! Because most photographers are using the 300 Watt halogen bulb with this head to avoid thermally overloading it, the fuse may not be any higher in rating than 3.15 F or 6.3 FF (for 240VAC mains supply).

Because the old Bron heads do not have a glass dome over the flash bulb and modelling light assembly to protect against flying pieces of hot glass, I recommend installing a wire mesh contraption over the mouth of the 9" reflector and using it together with an umbrella/brolly so it faces away from people. Also, I hope that you are covered by very good liability insurance.

Question: How did you find out that one of the heads comes with a Hensel plug? Is it marked? Is it wired for Hensels? Open the plug and post an image for further help.

Hope this helps

Hans Strobl

Alias �misterStrobe�

Phil, have you gone thru the test I mentioned before? The relay has NOTHING to do with the trigger circuit as you assume. The relay you mention is part of the after-glow prevention circuit. It cuts off the unit from the mains supply for a fraction of a second following a discharge of the power capacitors thus preventing the tube from after-glow. Because your unit does not discharge the relay can not activated!!! It has normally closed contacts, meaning that it is ON, connecting the charging circuitry to the mains when not active! You are on the wrong track.

Let it be said, that I definitely do not encourage persons to do repairs on hazardous equipment such as flash units. Matter of fact, I intend to point out the complexity and hazards in repairing flash equipment and hoping that equipment in need of repair is given into the hands of professional repair men specialised in such work.

The power capacitors of the Bowens Monolite 200 are charged to a voltage level of 620 VDC, this is potentially lethal.

Hans Strobl

Phil, I forgot to mention: If you don't hear that weak ping of the high voltage spark the flash tube may still be OK, but the trigger circuitry has a fault. If this is the case you will have to give the unit away to a repair service.

Hans

Hi Phil, because you say that the neon of the charge indicator flashes I am pretty sure that the unit has a bad flash tube. To confirm this you have to go thru the following steps:

1. Check the trigger wire for continuity, perhaps it got disconnected or broken.

2. Charge the unit and listen for that weak PING sound when you trigger the flash unit in silence. Caution: Do not look in the direction of the flash tube, or better yet, close your eyes when you hit the OPEN FLASH button.

Hearing that weak sound would mean that there is a high voltage trigger pulse generated. But if the flash tube doesn't fire, it will have to be replaced. If you should have another Monolite in good working condition you may exchange the flash tube assemblies to confirm this.

Wear rubber gloves when you remove the flash tube assembly. Make sure the flash unit has been disconnected for an hour before you start to work on it. After removing the 2 screws of the tube assembly DO NOT TOUCH the flat contact springs.

You can get a complete flash tube assembly from Calumet for about 200 USD, or 85 BP. It is up to you to decide whether it is still worthwhile to invest in a replacement tube, after all, the unit is close to 30 years old. Perhaps you find a second hand tube on eBay.

Hope this helps

Hans Strobl

If you do not have the proper qualifications in electrical work---- do not attempt doing repairs yourself. Repair of flash equipment is hazardous work and can be fatal when electric shock occurs.

Sorry to say that I can only guess what is wrong with your units because I don't have the possibility of examining the units myself. The fact that there is no noticeable deformation or leakage on any of the capacitors could mean they are still good and the problem is somewhere else, but one can not be sure until proper tests are run. Besides capacitors there are many other things that can go bad and be the cause for the symptoms you describe. Replacing defective parts is relatively easy for a service technician to do, but first he has to find them.

Bad capacitors may generate gases which increase the pressure in the can to the point where the safety device is activated. If the current limiting resistors are heating up as much as you say one or more of the 8 capacitors should have blown. A service technician can only be sure about the condition of the capacitors if he takes a solder gun and removes them out of circuit for testing.

Power capacitors for photo flash use are of special construction to be able to deliver a high current discharge through the flash tube. Standard capacitors will not perform. The supplier you mentioned does not carry the photo flash type.

In replacing capacitors for the Bowens Monolites a services technician has to make sure they are carefully selected to balance electrically because the old Monolites are using series connection of 350 VDC capacitors to operate on 630 VDC. In the Monolite 800E two banks in series divided into 3 groups are used for flash power storage. Each bank will see about 315 VDC in a balanced system. If there is an imbalance the bank or group with the lower capacitance will be confronted with a higher voltage which is sometimes asking for trouble. When the voltage applied exceeds the insulation capability of the anode foil, liquid electrolyte and the separating paper layer the capacitor will react violently.

If the capacitors should be bad, having them replaced for a total cost of 100 BP by a competent service technician who knows what he is doing, I would consider this a bargain. If you are not sure that the capacitors get selected and balanced properly you are better off not to have the unit repaired.

Hope this helps

Hans

alias "misterStrobe" on the Bowens Forum

Sorry, my mistake. For 60 minutes delay the display should read 6.0. This means for every 0.1 step you will get 1 minute in time until shut-off.

Hans

Hello Joseph, you need to press the power setting UP-button and the DOWN-button simultaneously. The digital display will change from f-stop indication to timer indication. Ignore the zero on the display, e.g.: 0.5 will indicate a time span of 5 minutes until automatic shut-off. Using the up/down switches you can change the setting to suit your needs. Maximum is 0.60 for 60 minutes. If the automatic function is not wanted you can turn it off by changing the setting to zero (displayed -.-). After a 2 seconds pause the display will change to f-stop indication again.

Hope this helps.

Hans

Hello James, the easiest way to reduce the light output is to use deflectors available from Elinchrom. These are placed in front of the flash tube/modelling lamp assembly. They are designed to reduce hot spots and help in spreading the light more evenly. Their drawback in reducing the efficiency of the light former can be used to advantage in your situation.

You can make devices to reduce the efficiency of your flash units easily yourself. The umbrella fitting of the Prolinca head can be used to hold a rod to which diffusion material can be fastened.

Although I had no need for such a device I found this an interesting task to master, so I built one myself using material I found in my scrap box. The material I used for a diffuser is thin LEXAN (high temperate resistant) which I roughened up with sand paper, and the rod is of wood . I decided to place the diffuser between flash tube and modelling light bulb to keep it relatively small, so I had to cut it into a ring shape. If you want to place it in front of the modelling light you will have to cut a disk which needs to be somewhat larger in size. The position close to the flash bulb will keep the diffuser smaller and lighter in weight, and an additional light blocking effect can be achieved by riveting a thin flat aluminium ring slightly larger than the flash tube to the diffuser material. Keep the diffuser material about 12 mm (1/2 inch) away from the flash tube.

In lack of a Prolinca unit I had to use an old Bowens Mono to demonstrate the placement of the diffuser gadget.

Hope this helps

Hans<div></div>

I don't believe you will find this ominous 2400 Joule power pack/generator by looking at the Bowens products. Bowens, by the way, is not owned by Metz, but is a subsidiary of KJP (Keith, Johnson and Pelling, UK) who merged with Calumet (USA) to form Calumet International. Bowens produced a 2400 Joule unit named DUO 2400 about 3 years ago, but I bet this is not the model you are searching for.

Because Bogen Photo, now Bogen Imaging, is the owner of MULTIBLITZ Germany, who is producing the MULTIBLITZ MAGNOLUX 2400 power pack/generator, I would guess that this is what you are searching for. (www.multiblitz.com)

To round up the information on who owns who: Bogen Imaging International is now owned by VITEK GROUP PLC of London, UK, along with Manfrotto Group, IFF, Gitzo and others etc.

Hope this helps

Hans

If your monolights are all the same type and if they have two sync jacks each you may try daisy-chaining them with sync leads with plugs on both ends. Limit is usually two links, this will allow you to have a setup with three flash units. This is the cheapest I can think of.

Hope this helps.

Hans

Bernard, this is due to the time delay caused by the transmission and signal processing of the remote control. If your camera has a focal plane shutter and you use a speed faster than recommended you will have uneven exposure across the image area. When using a central/leaf type shutter you will have the effect of underexposure because it's leafs are closing already before the flash discharge has ended.

Kirk, what you say is correct. A leaf type shutter can sync with a flash at a higher speed setting as compared to a focal plane shutter. But when a time delay exist due to the remote triggering device you will have to use a longer shutter speed still to prevent any negative effects as I already outlined above.

A complete flash tube assembly is available through Calumet Photo. The part number is BW 1550 and the price is $ 199.99 plus shipping.

The Bowens 200 B was imported into the U.S. by Bogen Photo of N.J. in the early 80s. I doubt that they are still supporting the Bowens flash units, but you may give them a call (201) 818-9500.

You should consider that for the price you will have to spend for a single replacement tube you can probably get two second-hand units with good flash tubes through eBay. I would be very careful to spend any money on the repair of a Bowens/Bogen 200B. These units have a very high sync voltage of 200VDC. This could mean ruining a modern digital camera when using a sync cable. Even wireless trigger systems, radio or IR, are likely to be affected by this voltage.

Hope this helps.

1. I would not recommend getting the 8 Amp fuse from sources in Asia. When located in the U.S. you should be only using fuses which are approved by Underwriters Laboratories (UL).

2. There is no way for the current to increase when a voltage drop occurs. As the voltage drops there is a reduction in current. On the other hand, if there is a sudden surge of voltage the current drawn would increase. Most flash units are able to handle modest surges, but if the voltage becomes excessive the built-in safety devices will have to react to prevent damaging equipment and persons. Most flash units have a VDR (Voltage Dependent Resistor) across the mains supply terminals to guard against such voltage surges. For the 117 VAC mains supply a VDR with a voltage rating of 130 VAC would be the appropriate one. If the mains supply voltage reaches this value the VDR will conduct (short circuit) and subsequently the resulting high current will be blowing the fuse thus protecting the unit against damage.

In spite of what others say, Voltage spikes can very well bring a fuse to blow via secondary reaction due to a conducting (short circuiting) VDR across the mains supply terminals. These spikes have nothing to do with the power company, they may be generated by strong electric motors, welding units, etc. close by and are very short in duration, not long enough to trigger a fuse , but long enough to trigger the VDR.

3. Before replacing a fuse find out first why it blew in the first place. In all probability, it may be a defective unit or an excessive voltage surge/spike when the fuse blew while it was just standing there when it happened. In the state in which the power capacitors are already fully charged there is a current draw of about 0.5 amp average for the flash power circuitry; the modelling light (150 Watt halogen) will draw 1.3 amps. This is a total of 1.8 amps of current drawn while "just standing there" with the modelling light on. Therefore something must have happened inside the unit to be the cause for blowing the GFE 8 amps fuse. Before you take any actions, unscrew the modelling light bulb (150 W Halostar?) from the unit and test it to see whether it is still working. If it should be burned-out you have found the cause of the problem because when the filament in the 117 VAC halogen bulb breaks a strong arc-flash may be produced being fed from the mains supply and drawing a very heavy current for a short time. The fuse in the circuit must react fast enough to prevent the explosion of the already red hot quarz glass envelope. The bits of hot glass scattering about could set fabrics and paper on fire and injure people (models, customers, etc.). This is the reason why manufacturers of flash equipment specify a certain type of fuse to warrant that the supply circuit is interrupted fast enough before any damage or harm is done. Just keep in mind: If the bulb goes the fuse must go too.

So, if you find the halogen on your flash unit burned out you've got no problem, just replace the halogen bulb and the fuse.

If the halogen is still intact, you do have a problem. Send the unit back to the manufacturer, leaving the original fuse in the holder for them to see that you did not use a wrong fuse.

Here is additional information about fuse replacement:

The manufacturer of the EXCALIBUR 6400 flash unit specifies a type of fuse with certain characteristics for safe operation. This is more of a legal issue than an electrical one due to very stringent consumer protection laws in the U.S. and Canada.

I don't know why the manufacturer of the EXCALIBUR 6400 is not listing equivalent type fuses to the GFE 8amp fuse made by Circuit Interruption Technology, Inc., N.J.

The equivalent types are:

BUSSMANN type GMA 8A 250V

LITTLEFUSE type 235 8A 250 V

BELFUSE type 5MF 8 8A 250 V

These are also fast-blowing 20 mm cartridge type and they are approved by Underwriters Laboratories (UL). Stay away from other fuses unless they carry the IEC (International Electrical Commission) approval.

Although the replacement of the fuse with an electrically equivalent type sounds practical you should consider the legal aspects in view of consumer protection laws.

If the manufacturer of the flash unit specifies the CIT brand GFE 8 fuse exclusively, that's it. If the user is replacing a fuse with an equivalent type, the manufacturer is in the clear if equipment is damaged or people are harmed.

I hope this can be of help to you and others also.

"misterStrobe"