Need Help Repairing Profoto Monolight

[waffles]

I need help making a small repair to my Profoto ComPact Plus 600. Yesterday, I noticed a "rattling" sound coming from one of my lights. When I pulled the frosted glass dome off to investigate, one of the screws fell out. There are normally 4 screws that attach the silver faceplate of a Profoto light head to the black body: 1) There is a screw that is flush mounted 2) There is a screw with a spacer that holds the "left" spring 3) There is a screw with a spacer that holds the "right" spring, and 4) There is a screw with a spacer that locks both springs into place. The screw that fell out was #4.

After setting the screw aside, I noticed still more rattling coming from inside the body of the light. After much shaking, a small hex nut and a small locking washer fell out of the front vent holes. I inspected the rest of the light, and tested it, and everything appears to be in normal working order. I just can't secure the frosted glass dome to the front anymore

I was wondering if anyone knew how to re-attach the screw? Or, if anyone knew of a different website or a different forum where people discuss these kinds of repairs? What worries me, is that obviously the hex nut and the locking washer need to be secured to the back of the face plate at the same time as the screw and the spacer are being "screwed in" from the front of the face plate ... so I'm assuming that means I have to remove the entire face plate to effect a repair. I'd rather not pay $100+ to ship this light to Profoto to have them do something as simple as replacing a #2 Phillips head screw. But at the same time, I don't want to cause any further damage to my light.

Also, I would be willing to take the light somewhere local to have it repaired. I live in Houston, Texas. There used to be a professional strobe repair shop here called Photronics, but their phone number is no longer in service and I suspect they've gone out of business. If anyone knows of any other professional resources that are available in Houston, Austin, or Dallas ... please let me know! The only service centers listed on the Profoto website are located in New York, Arizona, and California

^^ This is the front of the light with the glass dome & modeling lamp removed. The small hole at the one o'clock position is supposed to hold the "locking" screw.

^^ This shows the screw, the spacer, the washer, the locking washer, and the hex nut that fell out of the light. How do I re-attach it?

 

[John Koehrer]

Well Poop! Looks like the faceplates gotta come off/out of the housing to me. I hate when this kinda thing happens.

 

[waffles]

Well Poop! Looks like the faceplates gotta come off/out of the housing to me. I hate when this kinda thing happens.

I've done some more research. Unfortunately, this is not as simple a repair as it looks. The screws at the 9 o'clock position and the 3 o'clock position screw into threaded receivers that run the length of the light body (which is also what the two screws on the rear of the light screw into.) But the screws at the 1 o'clock position and the 5 o'clock position are held on by the friction of the locking washer and hex nut only.

To make matters worse, the light actually has two metal faceplates! The silver, shiny plate you see in the picture is the "superficial" faceplate, and doesn't really do anything important. It covers a second, gunmetal grey faceplate (which you can see peaking through the vent holes at 12 o'clock, 2 o'clock, and 7 o'clock. The second faceplate is riveted to the modeling light socket, and is has three penetrations for the two electrodes and triggering clamp of the flashtube. The locking washer and the hex nut need to go on the reverse side of the gunmetal gray faceplate. I was hoping they could just go on the reverse side of the silver plate and live sandwhiched between the grey & silver plates ... but there isn't enough room.

I don't know how to remove the gray faceplate. I suspect it will involve some soldering. Does anyone have any idea?

Or can someone point me to a better resource where I can ask this question? It'll cost over $150+ to ship this round-trip for plus the actual cost of the repair.

 

[bdial]

Do the 9 and 3 o'clock receivers exit the back panel?
From what you describe, it sounds like the two plates are fastened together with the 1 and 5 o'clock screws then slipped into the housing and secured with the 9 and 3 o'clock fasteners. If you can loosen those enough to get to the back of the assembly you may be able to replace the screw that came out. You may need to cobble up or buy some sort of tool to hold the nut.

If it's made like my Bowens the outer case is just a shell that the innards slide into. Note that if you expose the inside circuitry, you need to be very careful about not touching anything because the capacitors can hold lethal voltages.

Another option might be to use a pop rivet instead of the screw and nut, the pop rivet can be inserted in the hole with no access required in the back.
It will make any future repair a bit challenging, as it would need to be drilled out to remove, but that might not become an issue.

 

[waffles]

From what you describe, it sounds like the two plates are fastened together with the 1 and 5 o'clock screws then slipped into the housing and secured with the 9 and 3 o'clock fasteners. If you can loosen those enough to get to the back of the assembly you may be able to replace the screw that came out.

Exactly! The grey faceplate can be pulled out just a little ... and moreso on the "bottom" side. It might be possible to replace the 5 o'clock screw this way, but not the 1 o'clock screw. The top of the faceplate barely budges, because that's where the trigger wire and two electrodes are attached. Its a spaghetti of cords & cables underneath.

 

[John Koehrer]

I really like the pop rivet idea.

When I was working in the trade one of the techs running into something like this "they must have grown it from a seed"

 

[Patrick Robert James]

You can probably get it back together yourself. I'd get a couple of hook type picks and put the strobe on a stand face down so gravity can help you. Put the nut and washer in and finagle them into place. Once you get the bolt started you just need some friction on the nut to hold it until it gets tight. You might want to put a drop of locktite on the bolt after you start it but before you screw it home so you don't have the problem again. If you have trouble locating the nut and washer, you could put a drop of superglue through the hole in the face then push the washer into place. When that dries it should be enough to hold it there while you mess around with the nut. You could get a thin piece of something stiff and lightly superglue the nut to it so you have some control over it. If you use locktite you could bypass using the friction washer if all else fails. I hope all that makes sense...

Hope that helps you and good luck!

 

[AgX]

Yes, in similar cases I had been successful these ways in cases where there no longer was access for a driver, in fiddling nuts back into position and get them screwed tight.

 

[mpirie]

Instead of rivets, you may be able to use "Rivnuts"?

They're widely used in aluminium fastenings and are effectively a rivet, but with a threaded centre, so once they're secured in place, you can fix and remove machine screws.

Mike

 

[waffles]

I don't think I can remove the grey faceplate without first un-plugging the wires that attach to the modeling lamp socket, the two eletrode sockets, and the triggering clamp. And I don't want to shock myself! Does anyone know how to discharge the capacitors safely?

 

[bdial]

Do you have a manual? It should have instructions on how to remove the flash tube for changing it. As I recall, on my Bowens, it's a matter of turning the unit off, and unplugging it then removing the flash tube. That doesn't discharge the capacitors, but the flash tube can be handled safely at that point.

 

[AgX]

Capacitators do not hold a charge foreever. Some devices even may have a feature of discharging at switching off.

The power contacts at a flash are charged the same time with the power capacitator. By pulling out a bit the flash tube at a studio flash you gain access to its two power electrodes and can meter the resting voltage. (Use the common isolated tips, do not contact them to the chassis.)

Regarding formulas a 2K , 50W resistor would be something to discharge a 400Wsec flash within 60sec. Just to give you an idea.